Stable formaldehyde-free microcapsules

ABSTRACT

The present invention relates to water-dispersible core-shell microcapsules essentially free of formaldehyde. In particular it concerns oligomeric compositions comprising, and the microcapsules obtained from, particular reaction product between a polyamine component and a particular mixture of glyoxal and a C 4-6  2,2-dialkoxy-ethanal. The present invention comprises also the invention&#39;s core-shell microcapsules as part of a perfuming composition or of a perfuming consumer product.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/702,377 filed Dec. 6, 2012, which is a 371 filing of InternationalPatent Application No. PCT/IB2011/052700 filed Jun. 21, 2011, whichclaims the benefit of U.S. Provisional Application No. 61/358,741 filedJun. 25, 2010, and claims priority to European Application No.10167348.1 filed Jun. 25, 2010.

TECHNICAL FIELD

The present invention relates to the field of perfumery. Moreparticularly, it concerns water-dispersible core-shell microcapsulesessentially free of formaldehyde.

The present invention comprises also the invention's core-shellmicrocapsules as part of a perfuming composition or of a perfumingconsumer product.

PRIOR ART

Microcapsules are a widely known type of products, generally used ascarrier of a liquid phase.

A specific type of said microcapsules is the so-called aminoplastmicrocapsules comprising an external wall obtained by reacting apolyamine (in general melamine, i.e. 2,4,6-triamino-1,3,5-triazine) andan aldehyde (almost always in fact formaldehyde). These microcapsulesare very useful in the case where the liquid core is a volatile compoundor composition, like perfumes, since they are able to break undercertain conditions liberating the volatile in a controlled manner.

However said capsules, which are essentially formaldehyde based, containalways residual amounts of free formaldehyde due to unreacted precursorsor a slow decomposition of the thermoset oligomers. Oligomers which areformaldehyde-free are nowadays desired due to regulatory concerns,therefore there is a need by the industry for formaldehyde freecore-shell microcapsules possessing performance similar to theformaldehyde based ones, which have the best performance in stabilityand product delivery.

Some attempts to obtain formaldehyde free microcapsules have beenpublished in the prior art. The most relevant one for the presentinvention is disclosed in WO 2009/100553. The systems described in thisdocument comprise an aminoplast oligomer obtained by reacting at least apolyamine and unclearly defined “substituted methylene moieties” whichare exemplified by hemi-acetal of glyoxal esters or by2,2-dimethoxy-ethanal (DME) or 2,2-diphenoxy-ethanal. In the facts, allcapsules concretively described are obtained by reacting melamine (asunique polyamine) and DME or methyl 2-hydroxy-2-methoxy-acetate as“substituted methylene moieties”. However we found that the performancesand stability of such capsules are not satisfactory for an industrialapplication, as shown further below in the Examples.

In relation to the oligomer of the present invention, it is worthmentioning WO 07/135,108. In this document there are disclosed resinsobtained by reacting an amine (e.g. melamine, urea, and mixture thereof)with a glyoxal monoacetal only (e.g. DME). Said resins are differentchemicals compared to the oligomers of the present invention, by theirchemical structure and molecular weight, and are used in the manufactureof ligneous materials, and the application for microcapsules is notevocated or suggested.

Therefore there is still a need for core-shell microcapsulesformaldehyde-free and having superior stability performances.

DESCRIPTION OF THE INVENTION

We have now surprisingly discovered a new type of formaldehyde-freeoligomers which are particular suitable for the preparation oncore-shell microcapsules, containing an oil core and having superiorstability compared to the prior art formaldehyde-free core-shellmicrocapsules of similar constitution.

Therefore a first object of the present invention is an oligomericcomposition comprising the reaction product of, or obtainable byreacting together:

-   1) a polyamine component in the form of melamine or of a mixture of    melamine and at least one C₁₋₄ compound comprising two NH₂    functional groups;-   2) an aldehyde component in the form of a mixture of glyoxal, a C₄₋₆    2,2-dialkoxy-ethanal and optionally a glyoxalate, said mixture    having a molar ratio glyoxal/C₄₋₆ 2,2-dialkoxy-ethanal comprised    between about 1/1 and 10/1; and-   3) a protic acid catalyst.

The term “glyoxal” is understood to mean both the free di-aldehyde form(i.e. OHC—CHO) and the hydrated forms (e.g. (HO)₂HC—CHO).

The term “glyoxalate” is understood to mean the glyoxalic acid or analkaline salt of glyoxalic acid (such as OHC—COONa or OHC—COOK) ormixture thereof. The term “glyoxalate” is also understood to mean boththe free aldehyde form (i.e. OHC—COOH) and the hydrated form (e.g.(HO)₂HC—COOH or (HO)₂HC—COONa).

For the sake of clarity, by the expression “an oligomeric composition”,or the similar, it is meant the normal meaning understood by a personskilled in the art, i.e. a mixture of oligomers, as reaction product,and other optional components. In the simplest embodiment of theinvention said optional embodiment can be, as non-limiting examples,water and/or unreacted reagent of the process (e.g. the acid catalyst).By “oligomer” it is meant a compound which is not itself a macropolymer,as is a resin, but rather a small size molecule comprising between about4 to 100, or even preferably 30, units derived from the monomericconstituents.

According to a particular embodiment of the present invention, theinvention's oligomers possess a molecular weight (MW) comprised betweenabout 200 g/mol and 2500 g/mol. In still another aspect of theinvention, said MW is comprised between about 220 g/mol and 1200 g/mol.

According to any one of the above embodiments of the present invention,as polyamine component it is used a mixture of melamine and at least oneC₁₋₄ compound comprising two NH₂ functional groups. According to any oneof the above embodiments of the present invention, said compound is aC₁₋₂ compound comprising two NH₂ functional groups. For the sake ofclarity, by the expression “C₁₋₄ compound comprising two NH₂ functionalgroups”, or the similar, it is meant a C₁₋₄ hydrocarbon compoundcomprising two NH₂ functional groups, and additionally said compound mayoptionally comprise from one to three nitrogen and/or oxygen atoms. Inparticular said compound is a C₁₋₂ compound comprising two NH₂functional groups and a carbonyl or a 1,2,4-triazole functional group.Non-limiting examples of said C₁₋₄ compound comprising two NH₂functional groups (diamino compound) can be urea,1H-1,2,4-triazole-3,5-diamine and mixtures thereof.

According to any one of the above embodiments of the present invention,it can be used mixtures with a molar ratio melamine/diamino compoundcomprised between about 4/1 and 1/4, or even comprised between about3.5/1 and 1/3.5, or alternatively between about 2/1 and 1/3, oralternatively between about 1.3/1 and 1/3. In the case where the diaminocompound is 1H-1,2,4-triazole-3,5-diamine, one may also mention molarratio melamine/1H-1,2,4-triazole-3,5-diamine comprised between about1.5/1 and 1/1.5.

For the sake of clarity, by the expression “C₄₋₆ 2,2-dialkoxyethanal” itis meant a 2,2-dialkoxyethanal having in total from 4 to 6 carbon atoms.According to an embodiment of the present invention, said C₄₋₆2,2-dialkoxyethanal can be 2,2-dimethoxy-ethanal, 2,2-diethoxy-ethanaland mixtures thereof.

According to any one of the above embodiments of the present invention,said aldehyde component has a molar ratio glyoxal/2,2-dialkoxy-ethanalcomprised between about 3/1 and 7/1, or even comprised between about2.2/1 and 6.5/1, or even comprised between about 1.4/1 and 6.5/1. Onemay also mention that in the case where the diamino compound is urea,then said glyoxal/2,2-dialkoxy-ethanal may advantageously be comprisedbetween about 3/1 and 6.1/1. One may also mention that in the case wherethe diamino compound is 1H-1,2,4-triazole-3,5-diamine, then saidglyoxal/2,2-dialkoxy-ethanal may advantageously be comprised betweenabout 1.4/1 and 2.2/1.

The aldehyde component may also include (as optional constituent) aglyoxalate. According to any one of the above embodiments of the presentinvention, when present, said glyoxalate is present in amounts such thatmolar ratio glyoxal/glyoxalate is comprised between about 4/1 and 1/1,or even comprised between about 3.5/1 and 2/1. According to any one ofthe above embodiments of the present invention, said glyoxalate ispresent and within amounts such as stated in the ratio mentioned above,in particular when the diamino compound is1H-1,2,4-triazole-3,5-diamine.

According to any one of the above embodiments of the present invention,the said polyamine component and the aldehyde component are admixed in aratio such that the molar ratio of total amine functional group/totalfree aldehyde functional group (also referred as(NH₂)_(tot)/(CHO)_(tot)) is comprised between about 2/1 and 1/2, or evencomprised between about 1.5/1 and 1/1.5, or alternatively between about1.2/1 and 1/1.2. For the purpose of clarity, a melamine accounts for 3amine functional group and the diamino compound, e.g. urea, for 2.Similarly glyoxal accounts for 2 free aldehyde functional groups and theC₄₋₆ 2,2-dialkoxy-ethanal or the glyoxalate accounts for 1 free aldehydefunctional group.

As a person skilled in the art understand and knows, said protic acid isa catalyst or initiator of the oligomerisation, and therefore saidprotic acid may react also with the other components and becoming, atleast partially, part of the oligomers formed. According to any one ofthe above embodiments of the present invention, said protic acidcatalyst is selected amongst mineral acids, C₁₋₆ mono or dicarboxylicacids and mixtures thereof. Non-limiting examples of such acids arephosphoric, nitric, sulfuric or hydrochloric acids, or acetic, formic,oxalic or glyoxilic acids. More specifically, said acid catalyst isselected amongst formic acid, acetic, glyoxylic acid and, nitric acidsand mixtures thereof.

According to any one of the above embodiments of the present invention,the oligomeric composition is obtained by reacting the variouscomponents in water and the oligomeric composition is obtained by asingle step process wherein all reagents are mixed together or by amultistep process wherein the reagents are reacted togethersubsequently.

According to any one of the above embodiments of the present invention,the oligomer is obtained by a process where all the various componentsare reacted together in water, and the pH of the final reaction mediumis preferably comprised between 6 and 8.

According to any one of the above embodiments of the present invention,the oligomer is obtained by a two-step process. In a first step, thepolyamine component is reacted with the aldehyde component in an aqueousmedium, at a basic pH. Then in a second step, there is added to thereaction medium the acid catalyst, so as to work at an acidic pH.

According to any one of the above embodiments of the present invention,the pH of said first step can be comprised between about 7 and 10, oreven between about 8.5 and 9.5. In still another aspect of theinvention, the temperature of reaction of the first step can becomprised between about 20° C. and 80° C., or even between about 40° C.and 80° C.

In still another aspect of the invention, said first step can be carriedout for about 0.1 hour to about 4 hours (reaction time). However, morespecifically, the reaction time of said first step depends on thetemperature of the reaction, and its pH and can be comprised, forexample, between about 1 hour to about 4 hours, for a temperaturecomprised between about 40° C. and about 80° C. and a pH between about 8and about 10. Alternatively said reaction time can be comprised, forexample, between about 0.5 hour to about 2 hours, for a temperaturecomprised between about 50° C. and about 80° C. and a pH between about 7and about 9.5.

The pH of said first step can be typically set up by adding to thereaction medium an adequate amount of potassium or sodium hydroxide.

According to any one of the above embodiments of the present invention,the said acid catalyst is added to the reaction mixture of the firststep in an amount sufficient to acidify the latter. The pH of saidsecond step can be comprised between about 4.0 and 6, or even betweenabout 4.5 and 5.5. In still another aspect of the invention, thetemperature of reaction of the first step can be comprised between about40° C. and 100° C., or even between about 50° C. and 90° C.

In still another aspect of the invention, said second step can becarried out for about 0.5 hour to about 4 hours (reaction time).However, more specifically, the reaction time of said first step dependson the temperature of the reaction, and its pH and can be comprised, forexample, between about 1 hour to about 2.5 hours, for a temperaturecomprised between about 50° C. and about 80° C. and a pH between about4.5 and about 5.5. Alternatively said reaction time can be comprised,for example, between about 0.5 hour to about 4 hours, for a temperaturecomprised between about 50° C. and about 80° C. and a pH between about4.5 and about 5.5.

As can be noticed, the result of such process is an aqueous solutioncomprising the invention oligomeric composition. Typically, the aqueoussolution comprises between about 30% and 70% of oligomeric composition(solid content), percentage being expressed on a w/w basis relative tothe total weight of the solution.

Said aqueous solution can be used directly for the process ofpreparation of the microcapsules, as described further below, or can bedried to provide the oligomeric composition.

The present invention's oligomeric composition differs, inter alia, fromprior art oligomers by the use in its preparation of glyoxal, and inparticular of a specific mixture of glyoxal and C₄₋₆ dialkoxyethanal.Without being bound by theory, it is believed that the specific use ofsaid aldehyde component provides oligomers with free aldehyde or free OHgroups (not available when using for instance only a2,2-dialkoxy-ethanal, as aldehyde). Said free OH groups are expected toallow a better cross-linking during the formation of the microcapsuleshell, translating into an improved stability and performance ofcore-shell microcapsules obtained using such oligomers, as shown furtherbelow.

Therefore, a second object of the present invention is a process forobtaining the above microcapsules using said oligomeric composition. Inother words, a process for the preparation of a core-shell microcapsule,said process comprising the steps of:

-   1) preparing an oil-in-water dispersion, wherein the droplet size is    comprised between 1 and 600 μm, and comprising at least an    oligomeric composition as defined above;-   2) optionally adding to the dispersion a C₁₋₄ compound comprising    two NH₂ functional groups;-   3) heating said dispersion;-   4) cooling said dispersion; and-   5) optionally drying the final dispersion to obtain the dried    core-shell microcapsule.

For the sake of clarity, by the expression “core-shell microcapsule”, orthe similar, in the present invention it is meant that the capsule has asize in the micron range (e.g. a mean diameter comprised between about 1and 600 μm) and comprises an external solid oligomers-based shell orwall and an internal continuous oil phase enclosed by the externalshell. In other words bodies like coacervates or extrudates (i.e. poroussolid phases containing droplets of a liquid) are not part of theinvention. According to an embodiment of the invention, the size of saidmicrocapsules, and consequently of the droplet size in step 1), iscomprised between about 5 and 200 μm.

The dispersion in step 1) comprises at least an oligomeric compositionof the invention as well as an oil. Said dispersion, as well known inthe art, may also comprise as optional components at least a polyoland/or at least a stabilizer.

For the sake of clarity, by the expression “dispersion”, in the presentinvention it is meant a system in which particles are dispersed in acontinuous phase of a different composition and specifically includes asuspension or an emulsions.

According to any one of the above embodiments of the present invention,the dispersion comprises between about 1% and 10% of oligomericcomposition, percentage being expressed on a w/w basis relative to thetotal weight of the dispersion. In still another aspect of theinvention, the dispersion comprises between about 1% and 5% ofoligomeric composition. In general the amount of oligomeric compositionpresent in the dispersion can also be defined as being comprised between5% and 15% of oligomeric composition on a w/w basis relative to thetotal weight of oil added in the dispersion.

According to any one of the above embodiments of the present invention,the dispersion comprises between about 10% and 50% of oil, percentagebeing expressed on a w/w basis relative to the total weight of thedispersion. In still another aspect of the invention, the dispersioncomprises between about 20% and 40% of oil.

By “oil” we mean here an organic phase that is a liquid at about 20° C.and which will be in the core of the core-shell capsules. According toany one of the above embodiments of the present invention, said oil canbe selected amongst a perfume, insecticide, malodor counteractingsubstance, fungicide, insect repellant, and the mixtures thereof.

According to any one of the above embodiments of the present invention,said oil is a perfume. Said perfume can be in the form of a pureperfuming ingredient or of a perfuming composition.

By “perfuming composition” it is meant here the normal meaning of theart, i.e. a composition comprising several perfuming ingredients andoptionally at least one suitable solvent and/or at least one perfumeryadjuvant.

By “perfuming ingredient” or “perfuming co-ingredient” it is meant herea compound, which is used in a perfuming preparation or a composition toimpart a hedonic effect. In other words such a co-ingredient, to beconsidered as being a perfuming one, must be recognized by a personskilled in the art as being able to impart or modify in a positive orpleasant way the odor of a composition, and not just as having an odor.

The nature and type of the perfuming co-ingredients present in the basedo not warrant a more detailed description here, which in any case wouldnot be exhaustive, the skilled person being able to select them on thebasis of his general knowledge and according to intended use orapplication and the desired organoleptic effect. In general terms, theseperfuming co-ingredients belong to chemical classes as varied asalcohols, lactones, aldehydes, ketones, esters, ethers, acetates,nitriles, terpenoids, nitrogenous or sulphurous heterocyclic compoundsand essential oils, and said perfuming co-ingredients can be of naturalor synthetic origin. Many of these co-ingredients are in any case listedin reference texts such as the book by S. Arctander, Perfume and FlavorChemicals, 1969, Montclair, N.J., USA, or its more recent versions, orin other works of a similar nature, as well as in the abundant patentliterature in the field of perfumery. It is also understood that saidco-ingredients may also be compounds known to release in a controlledmanner various types of perfuming compounds.

By “suitable solvent” we mean here a material which is practicallyneutral from a perfumery point of view, i.e. that does not significantlyalter the organoleptic properties of perfuming ingredients and isgenerally not miscible with water, i.e. possesses a solubility in waterbelow 10%, or even below 5%. Say solvent is in general a solventcommonly used in perfumery, such as for example dipropyleneglycol,diethyl phthalate, isopropyl myristate, benzyl benzoate,2-(2-ethoxyethoxy)-1-ethanol or ethyl citrate, limonene or otherterpenes, isoparaffins such as those known under the trademark Isopar®(origin: Exxon Chemical) or glycol ethers and glycol ether esters suchas those known under the trademark Dowanol® (origin: Dow ChemicalCompany).

By “perfumery adjuvant” we mean here an ingredient capable of impartingadditional added benefit such as a color, a particular light resistance,chemical stability, etc. A detailed description of the nature and typeof adjuvant commonly used in perfuming bases cannot be exhaustive, butit has to be mentioned that said ingredients are well known to a personskilled in the art.

According to an embodiment of the invention, the dispersion comprisesalso between about 0% and 5% of at least a stabilizer, percentage beingexpressed on a w/w basis relative to the total weight of the dispersion.In still another aspect of the invention, the dispersion comprisesbetween about 0% and 2% of at least a stabilizer. In still anotheraspect of the invention, the dispersion comprises between about 0% and0.5% of at least a stabilizer. In the case where the aldehyde componentcomprises also a glyoxalate, and in particular when the diamino compoundis 1H-1,2,4-triazole-3,5-diamine, the dispersion comprises the amount ofsaid stabilizer is 0% (no addition of stabilizer).

For the sake of clarity, in the present context by the expression“stabilizer”, or the similar, it is meant the normal meaning understoodby a person skilled in the art, i.e. a compound that is capable, or isadded to, stabilize the system, e.g. to prevent aggregation oragglomeration of the microcapsules, for example in the application orduring their preparation. The use of said stabilizer is standardknowledge of the person skilled in the art.

For the purpose of the present invention, said stabilizer can be a ionicor non-ionic surfactant or a colloidal stabilizer. The exact nature ofsuch stabilizers is well known by a person skilled in the art. As nonlimiting examples one may cite the followings stabilizers: non-ionicpolymers such as polyvinyl alcohol, cellulose derivatives suchhydroxyethyl cellulose, polyethylene oxide, co-polymers of polyethyleneoxide and polyethylene or polypropylene oxide, co-polymers alkylacrylates and N-vinylpyrrolidone;

ionic polymers such as co-polymers of acrylamide and acrylic acid (suchas Alcapsol® 144 from Ciba), e.g. acid/acrylamide copolymers producedfrom monomer mixture of acrylic acid and acrylamide wherein the acrylicacid content is in the range of from 30 to 70%, acid anionic surfactant(such as sodium dodecyl sulfate), acrylic co-polymers bearing asulfonate group (such as sodium poly(styrene sulfonate), and co-polymersof vinyl ethers and maleic anhydride.

According to any one of the above embodiments of the present invention,said stabilized is a ionic surfactant.

According to any one of the above embodiments of the present invention,the dispersion comprises also between about 0% and 10% of at least apolyol, percentage being expressed on a w/w basis relative to the totalweight of the dispersion, or even comprised between about 0% and 2% ofat least a polyol. In still another aspect of the invention, when thediamino compound is urea, said amount can be comprised between about0.1% and 2% of at least a polyol. In still another aspect of theinvention, when the diamino compound is 1H-1,2,4-triazole-3,5-diamine,said amount can be comprised between about 0% and 1.5% or 1% of at leasta polyol.

For the sake of clarity, by the expression “polyol”, or the similar, itis meant the normal meaning understood by a person skilled in the art,i.e. a compound comprising one or more alcohol functional groups and isgenerally used to help the reticulation/curing/deposition of themicrocapsule's shell. The use of said polyol is standard knowledge ofthe person skilled in the art.

Said polyol may be selected from aromatic, aliphatic and polymericpolyols. As non-limiting examples one may cites aromatic polyol such as3,5-dihydroxy toluene, resorcinol, xylenol, bisphenol, polyhydroxynaphthalene, polyphenol obtained by the degradation of cellulose;aliphatic polyol such as humic acids, 2,2,-dimethyl-1,3-propane diol,1,1,1-tris-(hydroxymethyl)-propane, pentaerythritol, sorbitol or sugarderivatives and the similar; polymeric polyols such as celluloses orcarboxymethyl cellulose derivatives such as alkaline salts ofcarboxymethyl cellulose (e.g. and in particular a sodium salt likeAmbergum® 1221 (from HERCULES AQUALON)).

According to any one of the above embodiments of the present invention,said polyol is an aliphatic polymeric polyol such as a carboxymethylether cellulose derivative (such as, and in particular, Ambergum® 1221)or a chlorinated sugar such as sucralose.

Typical manners to form the dispersions of step 1) are known by a personskilled in the art, and are also described in the Examples herein below.

According to any one of the above embodiments of the present invention,the pH of said dispersion is set between 4 and 8. In still anotheraspect of the invention, the pH of said dispersion is comprised between4.0 and 7.0. The dispersion may be stirred up to 24000 rpm to disperseoil in water (with mechanical stirrer, ultra Turrax or microwave).

According to any one of the above embodiments of the present invention,the thus obtained dispersion may be kept at room temperature oroptionally heated at a temperature comprised between 30° C. and 70° C.In still another aspect of the invention, the temperature of saiddispersion is comprised between 35° C. and 60° C. Said heating may becarried on for between about 0.5 hour and 6 hours. More specifically,the time of heating depends on the temperature and the pH of saidemulsion or dispersion, and for example can be comprised between about 1hour to about 2.5 hours, for a temperature comprised between about 35°C. and about 60° C. and a pH between about 4.5 and about 8.

According to the invention's process, it may be possible to add to thedispersion an appropriate amount of a C₁₋₄ compound comprising two NH₂functional groups (diamino compound) as defined above. It is believedthat said step helps the hardening of the microcapsule shell. Said stepcan be attractive in particular when there is used an oligomer whereinthe NH_(2tot)/CHO_(tot) ratio is close to the minimum of the rangespecified above.

According to any one of the above embodiments of the invention'sprocess, said step 2) is performed (i.e. not optional). Said C₁₋₄compound comprising two NH₂ functional groups (diamino compound) can beurea, 1H-1,2,4-triazole-3,5-diamine and mixtures thereof.

According to any one of the above embodiments of the invention, in step2) there is added an amount of diamino compound comprised between about5% and 100%, or even between about 10% and 80%, or alternatively betweenabout 15% and 75%, percentage being expressed on a w/w basis relative tothe total weight of the resin. It is clearly understood by a personskilled in the art, that only part of said added diamino compound willbe incorporated into the microcapsule shell.

According to any one of the above embodiments of the invention, in step3) the dispersion is heated at a temperature comprised between 60° C.and 100° C. In still another aspect of the invention, the temperature ofsaid emulsion of dispersion is comprised between 70° C. and 90° C. Saidthermal treatment may be carried on for between about 0.5 hour and 6hours. More specifically, the time of heating depends on the temperatureand the pH of said emulsion or dispersion, and for example can becomprised between about 1 hour to about 5 hours, for a temperaturecomprised between about 70° C. and about 80° C. and a pH between about4.5 and about 8.

Step 4) of the invention's process is meant to stop the process ofhardening of the shell of the thus obtained core-shell microcapsule, andcan be performed by any known method. Typically, the dispersion can becooled at temperatures comprised between about 10° and 30° C., ingeneral to room temperature.

Said step 4) may optionally include a neutralization of the thusobtained dispersion at a pH comprised between pH between 6.5 and 7.5,for example by adding an appropriate amount of a base such as sodiumhydroxide.

As noticed above, the result of such process is an aqueous dispersion(or slurry) comprising the invention core-shell microcapsule. Typically,the aqueous slurry comprises between 10% and 50% of capsules, percentagebeing expressed on a w/w basis relative to the total weight of theslurry. According to any one of the above embodiments of the invention,the aqueous slurry comprises between 20% and 50% of capsules.

Said aqueous slurry can be used directly as perfuming ingredient, inparticular for applications which are aqueous based, e.g. a softener ora liquid soap. Therefore another object of the present invention is anaqueous slurry comprising the invention's microcapsules, for example aslurry as obtained directly for the process of preparation of themicrocapsules. Said slurry may further comprise some formulation aids,such as stabilizer or viscosity control agents, or even biocides orbactericides.

Alternatively, the slurry obtained by the process described above can besubmitted to a drying, like spay drying, to provide the microcapsules assuch, i.e. in a powdery form. It is understood that any standard methodknown by a person skilled in the art to perform such drying is alsoapplicable.

For the reasons set above, another object of the present invention is acomposition of matter as obtained, or obtainable, by the above-describedprocess. It is understood by a person skilled in the art that saidcomposition of matter comprises the core-shell microcapsules in the dryform or as a water-suspension.

According to any one of the above embodiments of the invention, saidcore-shell microcapsules are those obtained by using in the invention'sprocess an oil-in water dispersion wherein the oil is a perfume oil and,said dispersion comprises

-   -   at least an oligomeric composition as defined above;    -   at least a stabilizer, as defined above;    -   at least a polyol, as defined above; and    -   adding at least a C₁₋₄ compound comprising two NH₂ functional        groups, as defined above (step 2 of the invention's process).

According to any one of the above embodiments of said core-shellmicrocapsules, the amount of the core of oil accounts typically between40% and 98% of the total weight of the microcapsules (i.e. the weight ofthe dispersion minus the weight of water). In still another aspect ofthe invention, said core of oil accounts between 70% and 95%, or evenbetween 80% and 90%, of the total weight of the microcapsules.

According to any one of the above embodiments of said core-shellmicrocapsules, the amount of the shell accounts typically between 2% and60% of the total weight of the capsules. In still another aspect of theinvention, said oligomers-based shell accounts between 5% and 30%, oreven between 10% and 20%, of the total weight of the microcapsules.

According to any one of the above embodiments of said core-shellmicrocapsules, the amount of stabilizer is comprised between 5% and 15%,percentage being expressed on a w/w basis relative to the total weightof the shell (i.e. the solid content of the microcapsule in a dry form).In still another aspect of the invention, the amount of stabilizer iscomprised between 7% and 13%, percentage being expressed on a w/w basisrelative to the total weight of the shell.

According to any one of the above embodiments of said core-shellmicrocapsules, the amount of polyol is comprised between 1% and 5%,percentage being expressed on a w/w basis relative to the total weightof the shell. In still another aspect of the invention, the amount ofpolyol is comprised between 1.5% and 3%, percentage being expressed on aw/w basis relative to the total weight of the shell.

According to any one of the above embodiments of said core-shellmicrocapsules, the amount of C₁₋₄ compound comprising two NH₂ functionalgroups is comprised between 2% and 30%, percentage being expressed on aw/w basis relative to the total weight of the shell. In still anotheraspect of the invention, the amount of C₁₋₄ compound comprising two NH₂functional groups is comprised between 5% and 20%, percentage beingexpressed on a w/w basis relative to the total weight of the shell.

According to any one of the above embodiments of said core-shellmicrocapsules, the amount of oligomeric composition (in a dry form, as aclear for a person skilled in the art) is comprised between 50% and 95%,percentage being expressed on a w/w basis relative to the total weightof the shell. In still another aspect of the invention, the amount ofoligomers is comprised between 65% and 90%, percentage being expressedon a w/w basis relative to the total weight of the shell.

According to any one of the above embodiments of the invention, saidcore-shell microcapsules are those obtained by using in the invention'sprocess an oil-in water dispersion wherein the oil is a perfume oil andcomprising

at least an oligomeric composition as defined above and comprising aglyoxalate;

optionally at least a polyol, as defined above;

and wherein there is added during the process also at least a C₁₋₄compound comprising two NH₂ functional groups, as defined above (step 2of the invention's process), i.e. a process providing microcapsulescapsules comprising glyoxalate and not comprising a stabilizer.

As mentioned above, the invention concerns the use of an invention'smicrocapsule as perfuming ingredient. In other words, it concerns amethod to confer, enhance, improve or modify the odor properties of aperfuming composition or of a perfumed article, which method comprisesadding to said composition or article an effective amount of at least aninvention's microcapsule. By “use of an invention's microcapsule” it hasto be understood here also the use of any composition containing aninvention's microcapsule and which can be advantageously employed inperfumery industry.

Said compositions, which in fact can be advantageously employed asperfuming ingredients, are also an object of the present invention.

Therefore, another object of the present invention is a perfumingcomposition comprising:

-   i) as perfuming ingredient, at least one invention's microcapsule,    or a slurry containing said invention's microcapsule, as defined    above;-   ii) at least one ingredient selected from the group consisting of a    liquid perfumery carrier and a perfumery base; and-   iii) optionally at least one perfumery adjuvant.

By “liquid perfumery carrier” we mean here a liquid material which ispractically neutral from a perfumery point of view, i.e. which does notsignificantly alter the organoleptic properties of perfumingingredients.

As liquid perfumery carrier one may cite, as non-limiting examples, anemulsifying system, i.e. a solvent and a surfactant system, or a solventcommonly used in perfumery. A detailed description of the nature andtype of solvents commonly used in perfumery cannot be exhaustive.However, one can cite as non-limiting example solvents such asdipropyleneglycol, diethyl phthalate, isopropyl myristate, benzylbenzoate, 2-(2-ethoxyethoxy)-1-ethanol or ethyl citrate, which are themost commonly used. For the compositions which comprise both a perfumerycarrier and a perfumery base, other suitable perfumery carriers, thanthose previously specified, can be also ethanol, water/ethanol mixtures,limonene or other terpenes, isoparaffins such as those known under thetrademark Isopar® (origin: Exxon Chemical) or glycol ethers and glycolether esters such as those known under the trademark Dowanol® (origin:Dow Chemical Company).

By “perfumery base” we mean here a composition comprising at least oneperfuming co-ingredient, as defined above. The expression “perfumeryadjuvant” is as defined above.

An invention's composition consisting of at least one invention'smicrocapsule and at least one perfumery carrier represents a particularembodiment of the invention as well as a perfuming compositioncomprising at least one invention's microcapsule, at least one perfumerycarrier, at least one perfumery base, and optionally at least oneperfumery adjuvant.

It is useful to mention here that the possibility to have, in thecompositions mentioned above, more than one invention's microcapsule isimportant as it enables the perfumer to prepare accords, perfumes,possessing the odor tonality of various compounds of the invention,creating thus new tools for his work.

Furthermore, the invention's core-shell microapsules can also beadvantageously used in all the fields of modern perfumery, i.e. fine orfunctional perfumery, to positively impart or modify the odor of aconsumer product into which said invention's microcapsules are added.Consequently, a perfuming consumer product which comprises:

i) as perfuming ingredient, at least one invention's microcapsule, asdefined above; and

ii) a perfumery base; is also an object of the present invention.

Said fine or functional perfumery may be a solid or a liquid product.According to a particular embodiment, liquid products are preferred.

For the sake of clarity, it has to be mentioned that, by “perfumingconsumer product” it is meant a consumer product which is expected todeliver at least a perfuming effect, in other words it is a perfumedconsumer product. For the sake of clarity, it has to be mentioned that,by “perfumery base” we mean here a consumer product which is compatiblewith perfuming ingredients and is expected to deliver a pleasant odor tothe surface to which it is applied (e.g. skin, hair, textile, or homesurface). In other words, a perfuming consumer product according to theinvention comprises the functional formulation, as well as optionallyadditional benefit agents, corresponding to the desired consumerproduct, e.g. a detergent or an air freshener, and an olfactiveeffective amount of at least one invention's compound.

The nature and type of the constituents of the fine or functionalperfumery base do not warrant a more detailed description here, which inany case would not be exhaustive, the skilled person being able toselect them on the basis of his general knowledge and according to thenature and the desired effect of said product.

Non-limiting examples of suitable fine or functional perfumery base canbe a perfume, such as a fine perfume, a cologne or an after-shavelotion; a fabric care product, such as a liquid or solid detergent, afabric softener, a fabric refresher, an ironing water, a paper, or ableach; a body-care product, such as a hair care product (e.g. ashampoo, a coloring preparation or a hair spray), a cosmetic preparation(e.g. a vanishing cream or a deodorant or antiperspirant), or askin-care product (e.g. a perfumed soap, shower or bath mousse, oils orgel, or a hygiene product); an air care product, such as an airfreshener or a “ready to use” powdered air freshener; or a home careproduct, such as a wipe, a dish detergent or hard-surface detergent.

According to an embodiment of the invention, the fine or functionalperfumery base is in the form of a fabric, home, or hair care product,such as a fabric softener, a detergent or a shampoo.

Some of the above-mentioned consumer product bases may represent anaggressive medium for the invention's compound, so that it may benecessary to protect the latter from premature decomposition, forexample by encapsulation or by chemically bounding it to anotherchemical which is suitable to release the invention's ingredient upon asuitable external stimulus, such as an enzyme, light, heat or a changeof pH.

The proportions in which the compounds according to the invention can beincorporated into the various aforementioned articles or compositionsvary within a wide range of values. These values are dependent on thenature of the article to be perfumed and on the desired organolepticeffect as well as the nature of the co-ingredients in a given base whenthe compounds according to the invention are mixed with perfumingco-ingredients, solvents or additives commonly used in the art.

For example, in the case of perfuming compositions, typicalconcentrations are in the order of 0.001% to 5% by weight, or even more,of the compounds of the invention based on the weight of the compositioninto which they are incorporated. Concentrations lower than these, suchas in the order of 0.01% to 3% by weight, can be used when thesecompounds are incorporated into perfumed articles, percentage beingrelative to the weight of the article.

BRIEF DESCRIPTION OF THE DRAWINGS

In all figures the vertical axis represents the weight loss inpercentage of the slurry containing the microcapsules and as obtained bythe process of preparation of the latter.

FIG. 1a : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 1-3 (oligomeric composition 1), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 1b : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 4 and 5 (oligomeric composition), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 2a : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 6 and 7 (oligomeric composition 3), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 2b : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsule 9 (oligomeric composition 4), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 3a : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 10 and 11 (oligomeric composition 5), versusComparative microcapsule 1 (Comparative oligomers 3, prior art WO2009/100553).

FIG. 3b : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 12 to 14 (oligomeric composition 6), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 4a : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 15 and 16 (oligomeric composition 7), versusComparative microcapsule 1 (Comparative oligomers 3, prior art WO2009/100553).

FIG. 4b : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 17 (oligomeric composition 6), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 5a : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 19 (oligomeric composition 8) and 20 (oligomericcomposition 9), versus Comparative microcapsule 1 (Comparative oligomers3, prior art WO 2009/100553).

FIG. 5b : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 3 (oligomeric composition 1), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553), andComparative microcapsule 4 (Comparative oligomers 5).

FIG. 6a : TGA analysis at 50° C. of a slurry obtained by the preparationof microcapsules 9 (oligomeric composition 4), versus Comparativemicrocapsule 1 (Comparative oligomers 3, prior art WO 2009/100553, noadded urea in the process) and comparative microcapsules 2 and 3(Comparative oligomers 3, prior art WO 2009/100553, with added urea inthe process).

FIG. 6b : TGA analysis at 280° C. of a slurry obtained by thepreparation of microcapsules 20 (oligomeric composition 12) andmicrocapsules 21 (oligomeric composition 12), versus Comparativemicrocapsule 5 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 7a : TGA analysis at 280° C. of a slurry obtained by thepreparation of microcapsules 21 (oligomeric composition 12) andmicrocapsules 22 (oligomeric composition 12), versus Comparativemicrocapsule 5 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 7b : TGA analysis at 280° C. of a slurry obtained by thepreparation of microcapsules 23 (oligomeric composition 12),microcapsules 24 (oligomeric composition 12, prepared at 70° C.) andmicrocapsules 24 (oligomeric composition 12, prepared at 80° C.), versusComparative microcapsule 5 (Comparative oligomers 3, prior art WO2009/100553).

FIG. 8a : TGA analysis at 280° C. of a slurry obtained by thepreparation of microcapsules 23 (oligomeric composition 12),microcapsules 26 (oligomeric composition 12), microcapsules 27(oligomeric composition 12), microcapsules 28 (oligomeric composition12) and microcapsules 29 (oligomeric composition 12), versus Comparativemicrocapsule 5 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 8b : TGA analysis at 280° C. of a slurry obtained by thepreparation of microcapsules 29 (oligomeric composition 12),microcapsules 30 (oligomeric composition 10), microcapsules 31(oligomeric composition 11) and microcapsules 32 (oligomeric composition6), versus Comparative microcapsule 5 (Comparative oligomers 3, priorart WO 2009/100553).

FIG. 9a : TGA analysis at 300° C. of a slurry obtained by thepreparation of microcapsules 33 (oligomeric composition 13),microcapsules 34 (oligomeric composition 13), microcapsules 36(oligomeric composition 13), and microcapsules 35 (oligomericcomposition 13), versus Comparative microcapsule 5 (Comparativeoligomers 3, prior art WO 2009/100553).

FIG. 9b : TGA analysis at 300° C. of a slurry obtained by thepreparation of microcapsules 34 (oligomeric composition 13) andmicrocapsules 37 (oligomeric composition 13), versus Comparativemicrocapsule 5 (Comparative oligomers 3, prior art WO 2009/100553).

FIG. 10a : TGA analysis at 300° C. of a slurry obtained by thepreparation of microcapsules 36 (oligomeric composition 13),microcapsules 39 (oligomeric composition 13) and microcapsules 40(oligomeric composition 13), versus Comparative microcapsule 5(Comparative oligomers 3, prior art WO 2009/100553).

FIG. 10b : TGA analysis at 300° C. of a slurry obtained by thepreparation of microcapsules 36 (oligomeric composition 13) andmicrocapsules 41 (oligomeric composition 14), versus Comparativemicrocapsule 5 (Comparative oligomers 3, prior art WO 2009/100553).

EXAMPLES

The invention will now be described in further detail by way of thefollowing examples, wherein the abbreviations have the usual meaning inthe art, the temperatures are indicated in degrees centigrade (° C.).

TGA:

Solid content of resins was measured with a thermogravimetric analyser(Mettler-Toledo TGA/SDTA851^(e)) equipped with a microbalance (accuracy:1 μg) and an accurate oven having an internal volume of 35 ml, under aconstant nitrogen flow of 20 ml/min. Resin (10 mg) was introduced inaluminium pan of 40 μl. The measurement started from 25° C. to 100° C.at 5° C./min, staid at 100° C. for 1 h, and finally to 200° C. at 10°C./min. The solid content was determined by doing the ratio betweenweight of sample (plateau) and the initial weight in the crucible.Capsule performance was assessed at 50° C. (FIGS. 1a-6a ), and 280° C.(FIGS. 6b-10b ) or 300° C. (FIGS. 9a-10b ) with a similarthermogravimetric analyser. Perfume evaporation was measured as afunction of time. Microcapsules dispersion (10 mg) was introduced inalumina pan of 70 μl. The measurement at 50° C. started from 25° C. to50° C. at 5° C./min, and then staid at 50° C. for 4 h. The measurementat 280° C. started from 25° C. to 280° C. at 5° C./min, and then staidat 280° C. for 1 h and 5 min. The measurement at 300° C. started from25° C. to 300° C. at 5° C./min, and then staid at 300° C. for 1 h. Aslower evaporation of the perfume oil with a long-lasting profile wasrelated to a more stable capsule.

TOF-MS:

The analysis of the resin compositions was carried out by liquidchromatography, with a TOF-MS detector (TOF High Resolution>10000,Agilent 1200 HPLC system Agilent G1969A MS TOF system composed of aMultimode source APCI+ESI) composed of a binary solvent manager (or pumpG1312b), and an Auto sampler (g1329a). This TOF detector can analyzeproduct having molecular weight up to 3000 g/mol. Analyses were carriedout in formic acid aqueous solution at 0.1 wt % at RT without columns.Method Standard: Water premix: Acid formic 0.1% (Biosolve n° 23244125ULC/MSD lot 550361). HPLC: 0.5 ml/min, injection volume: 1 μl withwelplate sampler (without column), temperature of thermostat: 60° C.(+/−0.1° C.). One blank run was performed between each sample.

MSD:

Multi mode Electro spray (ESI)+APCI Pos LCMSD TOF High Resolution 3 ppmacq. Source: Mode Positive, Charging Voltage 2000 V, V cap 2500 V,Corona 4 μA, drying gas N₂, 5 l/min at 325° C., nebuliser 30 psig at200° C. Fragmentor: 140 to 320 V. Scan range: 103 to 3000, onlinestandard for mass adjustment.

SEC:

Solutions of resins (0.5 wt %) were analyzed by size exclusionchromatography in formic acid 0.1 wt % and ammonium acetate 0.05Maqueous solution (mobile phase, pH=4.70). Analyses were carried out at30° C. with a flow of 0.45 ml/min, by using a ThermoFinnigan SurveyorLC-Pump and Autosampler (20 μL injected). The column used was suppliedby TOSOH BIOSCIENCE (TSKgel Super AW2500 6.0 mm ID, 15.0 cm L, polyvinylresin). Molecular weights were measured by using ThermoFinnigan SurveyorUV/VIS detector and a SpectraSystem RI-150 refractive index detector(35° C.). Detectors were calibrated with standard poly(ethylene glycol)from 106 to 1982 g/mol.

Materials: 2,2-dimethoxyethanal (DME), oxalaldehyde (glyoxal, GY), and2-oxoacetic acid (glyoxylic acid, AGY) were used as aqueous solutions at60%, 40% and 50% w/w, respectively. 1,3,5-triazine-2,4,6-triamine(Melamine, M), urea and 1H-1,2,4-triazole-3,5-diamine (guanazole, T,purity=88.6%) were used as received. Ambergum® 1221 was used as asolution at 2% w/w in water. Alcapsol 144 was dissolved in water at 20%w/w. Sodium hydroxide (NaOH) was dissolved in water at 30% w/w. Nitricacid was used as a solution at 30% w/w in water. Formic acid (Aldrich,Switzerland) was used as received.

Example 1 Preparation of Oligomers According to the Invention

Oligomeric Composition 1:

In a round bottom flask of 250 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 28 g, 222 mmol), urea (13.33 g, 222 mmol),2,2-dimethoxyacetaldehyde (DME, 38.5 g, 222 mmol) and oxalaldehyde(glyoxal (GY), 64.4 g, 444 mmol) were dissolved in water (11 g, 611mmol). The pH was adjusted with 0.51 g of sodium hydroxide aq. solutionat 30 wt % (pH=8.89). The mixture was heated at 60° C. for 20 minutes.Then, nitric acid (23.56 g, 112 mmol) was added to fix pH at 4.52. Themixture was heated at 60° C. for 4 h. Solution was stored in the fridge(pH=4.04). Solid content=51 wt % (measured by TGA). Molecular weights(MW)=275 to 601 g/mol (measured by SEC).

TABLE 1 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 28.00222 1 1/1 1/1 Urea 13.33 222 1 DME 38.50 222 1 2/1 GY 64.40 444 2Oligomeric Composition 2:

In a round bottom flask of 25 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 2.5 g, 19.9 mmol), urea (3.6 g, 59.5 mmol),2,2-dimethoxyacetaldehyde (DME, 6.2 g, 35.7 mmol) and oxalaldehyde (GY,10.4 g, 71.7 mmol) were dissolved in water (5 g, 277.8 mmol). The pH wasadjusted with 0.57 g of sodium hydroxide aq. solution at 30 wt %(pH=9.31). The mixture was heated at 60° C. for 20 minutes. Then, nitricacid was added to fix pH at 4.60. The mixture was heated at 60° C. for 4h. Solution was stored in the fridge (pH=4.73). Solid content=49.2 wt %(measured by TGA). MW=320 to 600 g/mol (measured by SEC).

TABLE 2 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 2.519.9 1 1/3 1/1 Urea 3.6 59.5 3 DME 6.2 35.7 1.8 2/1 GY 10.4 71.7 3.6Oligomeric Composition 3:

In a round bottom flask of 25 ml, melamine (5.0 g, 39.7 mmol), urea (0.8g, 13.1 mmol), 2,2-dimethoxyacetaldehyde (DME, 5.1 g, 29.1 mmol) andoxalaldehyde (GY, 8.4 g, 58.1 mmol) were dissolved in water (5 g, 277.8mmol). The pH was adjusted with 0.39 g of sodium hydroxide aq. solutionat 30 wt % (pH=9.02). The mixture was heated at 60° C. for 20 minutes.Then, nitric acid was added to fix pH at 4.40. The mixture was heated at60° C. for 4 h. Solution was stored in the fridge (pH=4.72). Solidcontent is 50.5 wt % (measured by TGA). MW=305 to 586 g/mol (measured bySEC).

TABLE 3 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 5.039.7 1 1/0.33 1/1 Urea 0.8 13.1 0.33 DME 5.1 29.1 0.73 2/1 GY 8.4 58.11.46Oligomeric Composition 4:

In a round bottom flask of 25 ml, melamine (6.0 g, 47.6 mmol),2,2-dimethoxyacetaldehyde (DME, 4.95 g, 28.5 mmol) and oxalaldehyde (GY,8.3 g, 57.0 mmol) were dissolved in water (5 g, 277.8 mmol). The pH wasadjusted with 0.39 g of sodium hydroxide aq. solution at 30 wt %(pH=9.02). The mixture was heated at 60° C. for 20 minutes. Then, nitricacid was added to fix pH at 4.40. The mixture was heated at 60° C. for 4h. Solution was stored in the fridge (pH=4.72). Solid content is 43.5 wt% (measured by TGA). MW=305 to 585 g/mol (measured by SEC).

TABLE 4 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 6.047.6 1 1/0 1/1 DME 4.95 28.5 0.6 2/1 GY 8.3 57.0 1.2Oligomeric Composition 5:

In a round bottom flask of 250 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 28 g, 222 mmol), urea (13.33 g, 222 mmol),2,2-dimethoxyacetaldehyde (DME, 38.5 g, 222 mmol) and oxalaldehyde(glyoxal (GY), 64.4 g, 444 mmol) were dissolved in water (11 g, 611mmol). The pH was adjusted with 2.03 g of sodium hydroxide aq. solutionat 30 wt % (pH=8.89). The mixture was heated at 60° C. for 10 minutes togive a white suspension which became more and more viscous (pH=7.15).Then, nitric acid (19 g, 90 mmol) was added to fix pH at 4.49. Themixture was heated at 60° C. for 4 h. Solution was stored in the fridge(pH=4.75). Solid content is 52.3 wt % (measured by TGA). MW=320 to 601g/mol (measured by SEC).

TABLE 5 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 28.00222 1 1/1 1/1 Urea 13.33 222 1 DME 21.40 123.3 0.56 4/1 GY 71.60 493.32.22Oligomeric Composition 6:

In a round bottom flask of 250 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 9.3 g, 74 mmol), urea (13.33 g, 222 mmol),2,2-dimethoxyacetaldehyde (DME, 12.8 g, 74 mmol) and oxalaldehyde(glyoxal (GY), 42.9 g, 296 mmol) were dissolved in water (11 g, 611mmol). The pH was adjusted with 1.3 g of sodium hydroxide aq. solutionat 30 wt % (pH=9.03). The mixture was heated at 60° C. for 20 minutes.Then, nitric acid (19.0 g, 90 mmol) was added to fix pH at 4.48. Themixture was heated at 60° C. for 4 h. Solution was stored in the fridge(pH=4.57). Solid content is 49 wt % (measured by TGA). MW=320 to 601g/mol (measured by SEC).

TABLE 6 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 9.374 1 1/3 1/1 Urea 13.3 222 3 DME 12.8 74 1 4/1 GY 42.9 296 4Oligomeric Composition 7:

In a round bottom flask of 250 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 12.6 g, 100 mmol), 2,2-dimethoxyacetaldehyde (DME, 5.8 g,33.3 mmol) and oxalaldehyde (glyoxal (GY), 19.4 g, 133.3 mmol) weredissolved in water (11 g, 611 mmol). The pH was adjusted with 1.16 g ofsodium hydroxide aq. solution at 30 wt % (pH=9.01). The mixture washeated at 60° C. for 5 minutes to give a white suspension which becamemore and more viscous. Then, nitric acid (18.6 g, 89 mmol) was added tofix pH at 0.67, followed by 4.5 g of sodium hydroxide aq. solution at 30wt % (pH=4.43). The mixture was heated at 60° C. for 4 h. Solution wasstored in the fridge (pH=4.10). Solid content is 41.4 wt % (measured byTGA). MW=334 to 615 g/mol (measured by SEC).

TABLE 7 Ratio of the various starting materials n Ratio Ratio RatioCompound m (g) (mmol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 12.6100 1 1/0 1/1 DME 5.8 33.3 0.33 4/1 GY 19.4 133.3 1.33Oligomeric Composition 8:

In a round bottom flask of 100 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 3.0 g, 23.8 mmol), urea (4.3 g, 71.5 mmol),2,2-dimethoxyacetaldehyde (DME, 2.9 g, 16.5 mmol) and oxalaldehyde(glyoxal (GY), 14.4 g, 99 mmol) were dissolved in water (5 g). The pHwas adjusted with 0.8 g of sodium hydroxide aq. solution at 30 wt %(pH=9.45). The mixture was heated at 60° C. for 20 minutes. Then, nitricacid (1.2 g, 5.7 mmol) was added to fix pH at 4.67. The mixture washeated at 60° C. for 4 h. Solution was stored in the fridge (pH=4.64).Solid content=46.7 wt % (measured by TGA). MW=305 to 601 g/mol (measuredby SEC).

TABLE 8 Ratio of the various starting materials n Ratio Ratio RatioCompound m (g) (mmol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 3.023.8 1 1/3 1/1 Urea 4.3 71.5 3 DME 2.9 16.5 0.69 6/1 GY 14.4 99 4.16Oligomeric Composition 9:

In a round bottom flask of 100 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 3.0 g, 23.8 mmol), urea (4.3 g, 71.5 mmol),2,2-dimethoxyacetaldehyde (DME, 1.8 g, 10.2 mmol) and oxalaldehyde(glyoxal (GY), 14.8 g, 102 mmol) were dissolved in water (4.5 g). The pHwas adjusted with 1.1 g of sodium hydroxide aq. solution at 30 wt %(pH=9.46). The mixture was heated at 60° C. for 20 minutes. Then, nitricacid (2.7 g) was added to fix pH at 4.49. The mixture was heated at 60°C. for 4 h. Solution was stored in the fridge (pH=4.75). Solidcontent=45.8 wt % (measured by TGA). MW=305 to 601 g/mol (measured bySEC).

TABLE 9 ratio of the various starting materials n Ratio Ratio RatioCompound m (g) (mmol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 3.023.8 1 1/3 1/1 Urea 4.3 71.4 3 DME 1.8 10.2 0.43 10/1 GY 14.8 102 4.3Oligomeric Composition 10:

In a round bottom flask of 250 ml, melamine (0.93 g, 8.80 mmol), urea(0.87 g, 14.00 mmol), DME (0.63 g, 6.00 mmol) and GY (1.40 g, 24.20mmol) were dissolved in water (10.00 g, 556.00 mmol). The pH wasadjusted with 0.28 g of sodium hydroxide (pH=9.40). The mixture washeated at 60° C. for 20 minutes. Then, nitric acid (0.92 g, 4.30 mmol)was added to fix pH at 4.60. The resin can be use immediately to preparethe capsules.

TABLE 10 Ratio of the various starting materials n Ratio Ratio RatioCompound m (g) (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 0.938.8 1 1/1.6 1/1 Urea 0.87 14.0 1.6 DME 0.63 6.0 1 4/1 GY 1.40 24.2 4Oligomeric Composition 11:

In a round bottom flask of 250 ml, melamine (0.93 g, 8.80 mmol), urea(1.09 g, 17.60 mmol), DME (0.71 g, 6.80 mmol) and GY (1.58 g, 27.30mmol) were dissolved in water (10.00 g, 556.00 mmol). The pH wasadjusted with 0.34 g of sodium hydroxide (pH=9.45). The mixture washeated at 60° C. for 20 min. Then, nitric acid (0.91 g, 4.30 mmol) wasadded to fix pH at 4.61. The resin can be use immediately to prepare thecapsules.

TABLE 11 Ratio of the various starting materials n Ratio Ratio RatioCompound m (g) (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 0.938.8 1 1/2 1/1 Urea 1.09 17.6 2 DME 0.71 6.8 1 4/1 GY 1.58 27.3 4Oligomeric Composition 12:

In a round bottom flask of 250 ml, melamine (4.67 g, 44.00 mmol), urea(6.69 g, 108.00 mmol), DME (4.02 g, 39 mmol) and GY (8.97 g, 155 mmol)were dissolved in water (5.50 g, 306.00 mmol). The pH was adjusted with2.23 g of sodium hydroxide (pH=9.67). The mixture was heated at 60° C.for 20 minutes. Then, nitric acid (4.04 g, 19 mmol) was added to fix pHat 4.62. The mixture was heated at 60° C. for 4 h. Solution was storedin the fridge (pH=4.65). Solid content is 64% (measured by TGA).

TABLE 12 Ratio of the various starting materials n Ratio Ratio RatioCompound m (g) (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 4.67 441 1/2.45 1/1 Urea 6.69 108 2.45 DME 4.02 39 1 4/1 GY 8.97 155 4Oligomeric Composition 13:

In a round bottom flask of 50 ml, melamine (1.10 g, 8.78 mmol), DME(1.68 g, 9.69 mmol), AGY (0.72 g, 4.85 mmol) and GY (2.11 g, 14.54 mmol)were dissolved in water (1.90 g, 105.60 mmol). The pH was adjusted with0.95 g of sodium hydroxide (pH=9.10). The mixture was heated at 45° C.for 25 min. Then, water (8.35 g, 463.90 mmol) was added and stirred 5min. Guanazole (0.98 g, 8.74 mmol), previously dissolved in water (22.50mL) was added. The mixture was used immediately to make capsules.

TABLE 13 Ratio of the various starting materials Ratio n Ratio GY/DME/Ratio Compound m (g) (mol) eq. M/T AGY NH_(2tot)/CHO_(tot) Melamine 1.18.78 1 1/1 1/1 Guanazole 098 7.74 1 DME 1.68 9.69 1.1 3/2/1 GY 2.1114.55 1.66 AGY 0.72 4.85 0.55Oligomeric Composition 14:

In a round bottom flask of 50 ml, melamine (1.10 g, 8.78 mmol), DME(1.68 g, 9.69 mmol), AGY (0.72 g, 4.85 mmol) and GY (2.11 g, 14.54 mmol)were dissolved in water (1.9 g, 105.60 mmol). The pH was adjusted with0.95 g of sodium hydroxide (pH=9.10). The mixture was heated at 45° C.for 25 min. Then, water (8.35 g, 463.90 mmol) was added and stirred 5min. Guanazole (1.47 g, 13.08 mmol), dissolved in water (32.50 mL) wasadded. The mixture was used immediately to make capsules.

TABLE 14 Ratio of the various starting materials Ratio Ratio GY/DME/Ratio Compound m (g) n (mol) eq. M/T AGY NH_(2tot)/CHO_(tot) Melamine1.1 8.78 1 1/1.5 1.2/1 Guanazole 098 7.74 1 DME 1.68 9.69 1.1 3/2/1 GY2.11 14.55 1.66 AGY 0.72 4.85 0.55

Example 2 Preparation of Comparative Oligomers, Out of the Scope of thePresent Invention

Comparative Oligomers 1:

In a round bottom flask of 25 ml, urea (5.0 g, 83.0 mmol),2,2-dimethoxyacetaldehyde (DME, 5.8 g, 33.3 mmol) and oxalaldehyde (GY,9.7 g, 66.6 mmol) were dissolved in water (4 g, 222 mmol). The pH wasadjusted with 0.39 g of sodium hydroxide aq. solution at 30 wt %(pH=9.02). The mixture was heated at 60° C. for 20 minutes. Then, nitricacid was added to fix pH at 4.40. The mixture was heated at 60° C. for 4h. Solution was stored in the fridge (pH=4.72). Solid content is 48.2 wt% (measured by TGA). MW=334 to 601 g/mol (measured by SEC).

TABLE 1 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Urea 5.0 83.01 0/1 1/1 DME 5.8 33.3 0.4 2/1 GY 9.7 66.6 0.8Comparative Oligomers 2:

In a round bottom flask of 25 ml, urea (8.0 g, 133 mmol),2,2-dimethoxyacetaldehyde (DME, 5.1 g, 29.6 mmol) and oxalaldehyde(glyoxal (GY), 17.1 g, 118.4 mmol) were dissolved in water (4 g, 222mmol). The pH was adjusted with 5.33 g of sodium hydroxide aq. solutionat 30 wt % (pH=9.05). The mixture was heated at 60° C. for 20 minutes.Then, nitric acid was added to fix pH at 4.65. The mixture was heated at60° C. for 4 h. Solution was stored in the fridge (pH=4.73). Solidcontent is wt % (measured by TGA). MW=349 to 630 g/mol (measured bySEC).

TABLE 2 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Urea 8 133 10/1 1/1 DME 5.1 29.6 0.22 4/1 GY 17.1 118.4 0.89Comparative Oligomers 3: According to Prior Art WO 2009/100553

In a round bottom flask of 250 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 11.2 g, 89 mmol) and 2,2-dimethoxyacetaldehyde (DME, 30.8 g,178 mmol) were dissolved in water (3.7 g, 205 mmol). The pH was adjustedwith 0.27 g of sodium hydroxide aq. solution at 30 wt % (pH=9.53). Themixture was heated at 60° C. for 2 h to give a solution. Then, formicacid (1.02 g, 22 mmol) was added to fix pH at 4.50. The mixture washeated at 60° C. for 4 h. Solution was stored in the fridge (pH=4.23).MW=350 g/mol (measured by SEC).

TABLE 3 Ratio of the various starting materials Ratio Compound m (g) n(mol) eq. NH_(2tot)/CHO_(tot) Melamine 11.2 89 1 3/2 DME 30.8 178 2Comparative Oligomers 4:

In a round bottom flask of 100 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 2.8 g, 22.2 mmol), urea (4.0 g, 66.6 mmol), and oxalaldehyde(glyoxal (GY), 14.5 g, 100 mmol) were dissolved in water (4 g, 205mmol). The pH was adjusted with 1.78 g of sodium hydroxide aq. solutionat 30 wt % (pH=9.06). The mixture was heated at 60° C. for 20 minutes.Then, nitric acid (0.55 g, 2.6 mmol) was added to fix pH at 4.67. Themixture was heated at 60° C. for 4 h. Solution was stored in the fridge(pH=4.89). MW=305 to 601 g/mol (measured by SEC).

TABLE 4 Ratio of the various starting materials Ratio Ratio Compound m(g) n (mol) eq. M/U NH_(2tot)/CHO_(tot) Melamine 2.8 22.2 1 1/3 1/1 Urea4.0 66.6 3 GY 14.5 100.0 4.5Comparative Oligomers 5:

In a round bottom flask of 100 ml, 1,3,5-triazine-2,4,6-triamine(melamine, 5.0 g, 39.7 mmol), urea (2.4 g, 39.6 mmol),2,2-dimethoxyacetaldehyde (DME, 22.9 g, 132 mmol) and oxalaldehyde(glyoxal (GY), 4.8 g, 33.1 mmol) were dissolved in water (4 g). The pHwas adjusted with 0.83 g of sodium hydroxide aq. solution at 30 wt %(pH=9.24). The mixture was heated at 60° C. for 20 minutes. Then, nitricacid (1.91 g, 30.3 mmol) was added to fix pH at 4.56. The mixture washeated at 60° C. for 4 h. Solution was stored in the fridge (pH=4.95).Solid content=47.9 wt % (measured by TGA). MW=320 to 601 g/mol (measuredby SEC).

TABLE 5 Ratio of the various starting materials Ratio Ratio RatioCompound m (g) n (mol) eq. M/U GY/DME NH_(2tot)/CHO_(tot) Melamine 5.039.7 1 1/1 1/1 Urea 2.4 39.6 1 DME 22.9 132.0 4 1/4 GY 4.8 33.1 1

Example 3 Preparation of Core-Shell Microcapsules According to theInvention

Microcapsules 1:

In a 200 ml reactor, solutions of the polyol (Ambergum® 1221, 15.0 g, 2wt % in water) and oligomeric composition 1 as directly obtained inExample 1 (4.5 g) were dissolved in water (30.0 g) and stirred for 30minutes at RT (pH=4.55). Perfume oil (20.0 g, see Table below) was addedand the reaction mixture was sheared with ultra turrax at 24000 rpm for2 minutes. A solution of colloidal stabilizer was introduced (Alcapsol®144, 20 wt % in water, 0.4 g, pH=4.73). The reaction mixture was heatedat 40° C. for 1 h, then at 60° C. for 2 h, and finally at 75° C. for 3h. The resulting slurry was cooled down (pH=4.79) and neutralized with asolution of sodium hydroxide (30 wt % in water, 0.24 g, pH=6.37).

TABLE Perfume oil composition Raw material Amount (g) Romascone ® 4.0Verdox ® 4.0 Dorisyl ® 4.0 Lilial ® 4.0 Hexyl Salicylate 4.0

TABLE 1 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.43 2. Oligomeric composition 1 (51% w/w in water)4.50 3.27 3. Demineralised water 30.00 To balance 4. Perfume 20.00 28.535. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. NaOH (30% w/w inwater) 0.24 0.09 Total 70.14 100Microcapsules 2:

In a 200 ml reactor, solutions of Ambergum® 1221 (15.0 g, 2 wt % inwater) and oligomeric composition 1 as directly obtained in Example 1(4.5 g) were dissolved in water (30.0 g) and stirred for 30 minutes atRT (pH=4.53). Perfume oil (20.0 g, Table 2) was added and the reactionmixture was sheared with ultra turrax at 24000 rpm for 2 minutes. Asolution of colloidal stabilizer was introduced (Alcapsol® 144, 20 wt %in water, 0.4 g, pH=4.72). The reaction mixture was heated at 40° C. for1 h, and at 60° C. for 1 h. A solution of urea (50 wt %, 1.0 g) wasintroduced and reaction mixture was stirred at 60° C. for 1 h. Finally,mixture was heated at 75° C. for 3 h. The resulting slurry was cooleddown (pH=4.87) and neutralized with a solution of sodium hydroxide (30wt % in water, 0.23 g, pH=6.75).

TABLE 2 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 1 (51% w/w in water)4.50 3.22 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0028.12 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 1.00 0.70 7. NaOH (30% w/w in water) 0.23 0.10 Total 71.13 100Microcapsules 3.

In a 200 ml reactor, solutions of Ambergum® 1221 (30.0 g, 2 wt % inwater) and oligomeric composition 1 as directly obtained in Example 1(9.0 g) were dissolved in water (60.0 g) and stirred for 30 minutes atRT (pH=4.65). Perfume oil (40.0 g, Table 11) was added and the reactionmixture was sheared with ultra turrax at 24000 rpm for 2 minutes. Asolution of colloidal stabilizer was introduced (Alcapsol® 144, 20 wt %in water, 0.8 g, pH=4.58). The reaction mixture was heated at 40° C. for1 h, and at 60° C. for 1 h. A solution of urea (50 wt % in water, 4.0 g)was introduced at 60° C. and reaction mixture was stirred for 1 h.Finally, mixture was heated at 75° C. for 3 h. The resulting slurry wascooled down (pH=4.76) and neutralized with a solution of sodiumhydroxide (30 wt % in water, 0.47 g, pH=6.45).

TABLE 3 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.42 2. Oligomeric composition 1 (51% w/w in water)9.00 3.18 3. Demineralised water 60.00 To balance 4. Perfume oil 40.0027.72 5. Alcapsol ® 144 (20% w/w in water 0.80 0.11 6. Urea (50% w/w inwater) 4.00 1.39 7. NaOH (30% w/w in water) 0.47 0.11 Total 144.27 100Microcapsules 4.

The microcapsules were prepared as described for microcapsule 2, usingoligomeric composition 2.

TABLE 4 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 2 (49.2% w/w inwater) 4.50 3.21 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 27.99 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 1.00 0.70 7. NaOH (30% w/w in water) 0.15 0.06 Total 71.45100Microcapsules 5.

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 2.

TABLE 5 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 2 (49.2% w/w inwater) 4.50 3.07 3. Demineralised water 30.00 To balance 4. New-mix20.00 27.69 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 2.00 1.38 7. NaOH (30% w/w in water) 0.19 0.08 Total 72.09100Microcapsules 6:

The microcapsules were prepared as described for microcapsule 2, usingoligomeric composition 3.

TABLE 6 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.41 2. Oligomeric composition 3 (50.5% w/w inwater) 4.50 3.20 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 28.13 5. Alcapsol ® 144 (20%) 0.40 0.11 6. Urea (50% w/w in water)1.00 0.70 7. NaOH (30% w/w in water) 0.19 0.08 Total 71.09 100Microcapsules 7.

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 3.

TABLE 7 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.41 2. Oligomeric composition 3 (50.5% w/w inwater) 4.50 3.14 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 27.60 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 2.00 1.38 7. NaOH (30% w/w in water) 0.17 0.07 Total 72.47100Microcapsules 8:

The microcapsules were prepared as described for microcapsule 1, usingoligomeric composition 4.

TABLE 8 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 4 (43.5% w/w inwater) 4.50 2.78 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 28.37 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. NaOH (30%w/w in water) 0.19 0.08 Total 70.49 100Microcapsules 9.

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 4.

TABLE 9 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 4 (43.5% w/w inwater) 4.50 2.71 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 27.71 5. Alcapsol ® 144 (20%) 0.40 0.11 6. Urea (50% w/w in water)2.00 1.39 7. NaOH (30% w/w in water) 0.23 0.09 Total 72.13 100Microcapsules 10:

The microcapsules were prepared as described for microcapsule 2, usingoligomeric composition 5.

TABLE 10 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 5 (52.3% w/w inwater) 4.50 3.31 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 28.10 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 1.00 0.70 7. NaOH (30% w/w in water) 0.28 0.12 Total 71.18100Microcapsules 11:

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 5.

TABLE 11 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 5 (52.3% w/w inwater) 4.50 3.26 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 27.69 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 2.00 1.38 7. NaOH (30% w/w in water) 0.33 0.14 Total 72.23100Microcapsules 12:

The microcapsules were prepared as described for microcapsule 1, usingoligomeric composition 6.

TABLE 12 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.43 2. Oligomeric composition 6 (49% w/w in water)4.50 3.15 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0028.53 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. NaOH (30% w/w inwater) 0.21 0.09 Total 70.11 100Microcapsules 13:

The microcapsules were prepared as described for microcapsule 2, usingoligomeric composition 6.

TABLE 13 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 6 (49% w/w in water)4.50 3.10 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0028.12 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 1.00 0.70 7. NaOH (30% w/w in water) 0.30 0.10 Total 71.20 100Microcapsules 14:

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 6.

TABLE 14 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 6 (49% w/w in water)4.50 3.06 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0027.72 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 2.00 1.39 7. NaOH (30% w/w in water) 0.19 0.08 Total 72.09 100Microcapsules 15:

The microcapsules were prepared as described for microcapsule 2, usingoligomeric composition 7.

TABLE 15 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 7 (41.4% w/w inwater) 4.50 2.61 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 28.12 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 1.00 0.70 7. NaOH (30% w/w in water) 0.42 0.18 Total 71.32100Microcapsules 16:

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 7.

TABLE 16 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 7 (41.4% w/w inwater) 4.50 2.58 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 27.72 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 2.00 1.39 7. NaOH (30% w/w in water) 0.34 0.14 Total 72.24100Microcapsules 17:

In a 200 ml reactor, solutions of Ambergum® 1221 (15.0 g, 2 wt % inwater) and oligomeric composition 6 as directly obtained in Example 1(4.5 g) were dissolved in water (30.0 g) and stirred for 30 minutes atroom temperature (pH=4.49). Perfume oil (20.0 g, Table 11) was added andthe reaction mixture was sheared with ultra turrax at 24000 rpm for 2minutes. A solution of colloidal stabilizer was introduced (Alcapsol144, 20 wt % in water, 0.4 g, pH=4.52). The reaction mixture was heatedat 40° C. for 1 h, and at 60° C. for 1 h. A solution of1H-1,2,4-triazole-3,5-diamine (50 wt % in water, 2.0 g, >98%, Supplier:Alfa Aesar) was introduced at 60° C. and reaction mixture was stirredfor 1 h. Finally, mixture was heated at 75° C. for 3 h. The resultingslurry was cooled down (pH=5.02) and neutralized with a solution ofsodium hydroxide (30 wt % in water, 0.28 g, pH=7.06).

TABLE 17 w/w percentage of the various components introduced stepwise inthe dispersion Amount % Raw material (g) (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 6 (49% w/w in water)4.50 3.06 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0027.72 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6.1H-1,2,4-triazole-3,5-diamine (50% w/w in water) 2.00 1.39 7. NaOH (30%w/w in water) 0.27 0.08 Total 72.17 100Microcapsules 18:

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 8.

TABLE 18 w/w percentage of the various components introduced stepwise inthe dispersion % Raw material Amount (g) (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomers composition 8 (46.7% w/w in water)4.50 3.06 3. Demineralised water 30.00 41.60 4. Perfume oil 20.00 27.735. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 2.00 1.39 7. NaOH (30% w/w in water) 0.22 0.09 Total 72.12 100Microcapsules 19:

The microcapsules were prepared as described for microcapsule 3, usingoligomeric composition 9.

TABLE 19 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 9 (45.8% w/w inwater) 4.50 2.86 3. Demineralised water 30.00 To balance 4. Perfume oil20.00 27.73 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50%w/w in water) 2.00 1.39 7. NaOH (30% w/w in water) 0.19 0.09 Total 72.09100Microcapsules 20:

In a 200 ml reactor, solutions of polyol (Ambergum® 1221, 15.0 g, 2% inwater) and oligomeric composition 12 as directly obtained in Example 1(4.5 g) were dissolved in water (30.0 g) and stirred for 30 min at roomtemperature (pH=5.17). Perfume oil (20.0 g, Table 11) was added and thereaction mixture was sheared with ultra turrax at 24000 rpm for 2minutes. A solution of colloidal stabilizer was introduced (Alcapsol®144, 20% in water, 0.4 g, pH=5.27). Reaction mixture was heated at 40°C. for 1 h, and at 60° C. for 1 h. A solution of urea (50% in water, 2.0g) was introduced at 60° C. and reaction mixture was stirred for 1 h.Finally, mixture was heated at 75° C. for 3 h. The resulting slurry wascooled down (pH=5.31) and neutralized with a solution of sodiumhydroxide (30% in water, 0.30 g, pH=7.60).

TABLE 20 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Oligomeric composition 12 (64% in water)3.40 3.11 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0028.13 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 2.00 1.41 7. NaOH (30% w/w in water) 0.30 0.13 Total 70.14 100Microcapsules 21:

The microcapsules were prepared as described for microcapsule 20 with6.28% of oligomeric composition 12.

TABLE 21 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.39 2. Oligomeric composition 12 (~25.9% in water)18.37 6.28 3. Demineralised water 20.00 To balance 4. Perfume oil 20.0028.13 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 2.00 1.31 7. NaOH (30% w/w in water) 0.30 0.10 Total 76.03 100

Microcapsules 21 was prepared with 6.28% of oligomeric composition 12compared with microcapsules 20 prepared with 3.11% of oligomericcomposition 12. Higher concentration of resin improved capsulesstability. Stability of microcapsules 20 and 21 was improved comparedwith comparative microcapsules 5 (FIG. 6b /10).

Microcapsules 22:

The microcapsules were prepared as described for microcapsule 21 withguanazole to replace urea.

TABLE 22 w/w percentage of the various components introduced stepwise inthe dispersion Amount Raw material (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.39 2. Oligomeric composition 12 (~25.9% in water)18.67 6.27 3. Demineralised water 20.00 To balance 4. Perfume oil 20.0028.13 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Guanazole (50%w/w in water) 2.00 1.31 7. NaOH (30% w/w in water) 0.35 0.10 Total 76.42100

Microcapsules 21 were coated with urea compared with microcapsules 22coated with guanazole. Guanazole increased capsules stability. Stabilityof microcapsules 21 and 22 was improved compared with comparativemicrocapsules 5 (FIG. 7a /10).

Microcapsules 23:

In a 200 ml reactor, solutions of polyol (Ambergum® 1221, 30.0 g, 2% inwater) with 1H-1,2,4-triazole-3,5-diamine (2 g) and oligomericcomposition 12 as directly obtained in Example 1 (18.85 g, 25% in water)were stirred (pH=5.42). Perfume oil (20.0 g) was added and the reactionmixture was sheared with ultra turrax at 24000 rpm for 2 min. Themixture was heated at 60° C. for 6 h. The resulting slurry was cooleddown (pH=4.94) and neutralized with a solution of sodium hydroxide (30%in water, 0.42 g, pH=6.53).

TABLE 23 w/w percentage of the various components introduced stepwise inthe dispersion % Raw material Amount (g) (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.84 2. Oligomeric composition 12 (~25.2% in water)18.85 6.67 3. Guanazole (50% w/w in water) 2.00 2.49 4. Perfume oil20.00 28.05 5. NaOH (30% w/w in water) 0.42 0.21 Total 71.27 100Microcapsules 24:

The microcapsules were prepared as described for microcapsule 23 at 70°C.

TABLE 24 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.84 2. Oligomeric composition 12 18.85 6.67 (~25.2%in water) 3. Guanazole (50% w/w in water) 2.00 2.49 4. Perfume oil 20.0028.05 5. NaOH (30% w/w in water) 0.42 0.21 Total 71.27 100Microcapsules 25:

The microcapsules were prepared as described for microcapsule 23 at 80°C.

TABLE 25 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.84 2. Oligomeric composition 12 18.85 6.67 (~25.2%in water) 3. Guanazole (50% w/w in water) 2.00 2.49 4. Perfume oil 20.0028.05 5. NaOH (30% w/w in water) 0.42 0.21 Total 71.27 100

Microcapsules 23 were prepared at 60° C. for 6 h, whereas microcapsules24 and 25 were prepared at 70° C. and 80° C., respectively, for 6 h.Higher temperature of polymerization gave more stable microcapsules.Stability of microcapsules 23, 24 and 25 was improved compared withcomparative microcapsules 5 (FIG. 7b /10).

Microcapsules 26:

The microcapsules were prepared as described for microcapsule 23 with1.88% w/w of guanazole.

TABLE 26 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.84 2. Oligomeric composition 12 18.85 6.67 (~25.2%in water) 3. Guanazole (50% w/w in water) 1.50 1.88 4. Perfume oil 20.0028.24 5. NaOH (30% w/w in water) 0.44 0.19 Total 70.81 100Microcapsules 27:

The microcapsules were prepared as described for microcapsule 23 with1.26% w/w of guanazole.

TABLE 27 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.85 2. Oligomeric composition 12 18.85 6.67 (~25.2%in water) 3. Guanazole (50% w/w in water) 1.00 1.26 4. Perfume oil 20.0028.24 5. NaOH (30% w/w in water) 0.38 0.16 Total 70.21 100Microcapsules 28:

The microcapsules were prepared as described for microcapsule 23 with1.63% w/w of guanazole.

TABLE 28 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.85 2. Oligomeric composition 12 18.85 6.67 (~25.2%in water) 3. Guanazole (50% w/w in water) 1.30 1.63 4. Perfume oil 20.0028.39 5. NaOH (30% w/w in water) 0.35 0.15 Total 70.45 100Microcapsules 29:

The microcapsules were prepared as described for microcapsule 23 with1.76% w/w of guanazole.

TABLE 29 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.85 2. Oligomeric composition 12 18.85 6.67 (~25.2%in water) 3. Guanazole (50% w/w in water) 1.40 1.76 4. Perfume oil 20.0028.31 5. NaOH (30% w/w in water) 0.40 0.17 Total 70.65 100

Microcapsules 23 were coated with 2.49% of guanazole compared withmicrocapsules 26, 27, 28 and 29, coated with 1.88%, 1.26%, 1.63% and1.76% of guanazole, respectively. Concentration above 1.76% is optimal.Stability of microcapsules 23, 26, 27, 28 and 29 was improved comparedwith comparative microcapsules 5 (FIG. 8a /10).

Microcapsules 30:

The microcapsules were prepared as described for microcapsule 29, usingoligomeric composition 10.

TABLE 30 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.86 2. Oligomeric composition 10 18.31 6.15 (~23.5%in water) 3. Guanazole (50% w/w in water) 1.40 1.77 4. Perfume oil 20.0028.55 5. NaOH (30% w/w in water) 0.35 0.15 Total 70.06 100Microcapsules 31:

The microcapsules were prepared as described for microcapsule 29, usingoligomeric composition 11.

TABLE 31 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.87 2. Oligomeric composition 11 17.26 6.24 (~25%in water 3. Guanazole (50% w/w in water) 1.40 1.80 4. Perfume oil 20.0028.94 5. NaOH (30% w/w in water) 0.45 0.20 Total 69.11 100Microcapsules 32:

The microcapsules were prepared as described for microcapsule 29, usingoligomeric composition 6.

TABLE 32 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 40.46 0.83 2. Oligomeric composition 6 27.24 7.63 (~27.2%in water) 3. Guanazole (50% w/w in water) 1.89 1.75 4. Perfume oil 27.0027.82 5. NaOH (30% w/w in water) 0.47 0.15 Total 97.06 100

Microcapsules 29 were prepared with oligomeric composition 12, having amelamine/urea molar ratio of 1/2.45 compared with microcapsules 30(1/1.6), 31 (1/2), and 32 (1/3). Molar ratio below 4.5 gave more stablemicrocapsules. Stability of microcapsules 29, 30, 31 and 32 was improvedcompared with comparative microcapsules 5 (FIG. 8b /10).

Microcapsules 33:

In a 200 ml reactor, a solution of colloidal stabilizer (Alcapsol® 144,20% in water, 3.5 g, pH=5.75) in water (6.50 g) was dissolved inoligomeric composition 13 as directly obtained in Example 1 (40.29 g).Perfume oil (21.00 g) was added and the reaction mixture was shearedwith ultra turrax at 20000 rpm for 2 minutes. pH was adjusted at 5.43with formic acid (0.18 g). Reaction mixture was stirred at 300 r.p.m.and heated at 45° C. for 1.5 h then at 60° C. for 1.5 h, and finally at75° C. for 2 h. The resulting slurry was cooled down (pH=5.40) andneutralized with a solution of sodium hydroxide (0.43 g, pH=7.16).

TABLE 33 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Alcapsol ® 144 (20%w/w in water) 3.50 0.97 2. Demineralised water 6.50 To balance 3.Oligomeric composition 13 40.29 5.97 (10.66% in water) 4. Perfume oil21.00 29.21 5. Formic acid 0.18 0.25 6. NaOH (30% w/w in water) 0.430.18 Total 71.90 100Microcapsules 34.

In a 200 ml reactor, a solution of colloidal stabilizer (Alcapsol® 144,3.50 g, pH=5.75) in water (6.50 g) was dissolved in oligomericcomposition 13 as directly obtained in Example 1 (40.29 g). Perfume oil(21.00 g) was added and the reaction mixture was sheared with ultraturrax at 20000 rpm for 2 minutes. pH was adjusted at 5.42 with formicacid (0.20 g). Reaction mixture was stirred at 300 r.p.m. and heated at45° C. for 1 h then at 60° C. for 1 h, and finally at 80° C. for 3 h.The resulting slurry was cooled down (pH=5.45) and neutralized with asolution of sodium hydroxide (0.23 g, pH=6.82).

TABLE 34 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Alcapsol ® 144 (20%w/w in water) 3.50 0.99 2. Demineralised water 6.50 To balance 3.Oligomeric composition 13 40.29 6.07 (10.66% in water) 4. Perfume oil21.00 29.70 5. Formic acid 0.20 0.28 6. NaOH (30% w/w in water) 0.230.10 Total 70.70 100Microcapsules 35:

In a 200 ml reactor, a solution of colloidal stabilizer (Alcapsol® 144,3.5 g, pH=5.75) in water (6.50 g) was dissolved in oligomericcomposition 13 as directly obtained in Example 1 (40.29 g). Perfume oil(21.0 g) was added and the reaction mixture was sheared with ultraturrax at 20000 rpm for 2 minutes. pH was adjusted at 5.42 with formicacid (0.17 g). Reaction mixture was stirred at 300 r.p.m. and heated at55° C. for 3 h then at 75° C. for 2 h. The resulting slurry was cooleddown (pH=5.58) and neutralized with a solution of sodium hydroxide (30%in water, 0.61 g, pH=6.94).

TABLE 35 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Alcapsol ® 144 (20%w/w in water) 3.50 0.97 2. Demineralised water 6.50 To balance 3.Oligomeric composition 13 40.29 5.96 (10.66% in water) 4. Perfume oil21.00 29.13 5. Formic acid 0.17 0.24 6. NaOH (30% w/w in water) 0.610.25 Total 72.10 100

Microcapsules 33 were prepared with oligomeric composition 13 at 45° C.for 1.5 h, 60° C. for 1.5 h and finally at 75° C. for 2 h, compared withmicrocapsules 34, prepared at 45° C. for 1 h, 60° C. for 1 h and 80° C.for 3 h, and with microcapsules 35, prepared at 55° C. for 3 h and 75°C. for 2 h. Stability of microcapsules 33, 34 and 35 was improvedcompared with comparative microcapsules 5 (FIG. 9a /10).

Microcapsules 36:

In a 200 ml reactor, oligomeric composition 13, as directly obtained inExample 1 (40.29 g), was diluted with water (10.00 g) and perfume oil(21.00 g) was added. Reaction mixture was sheared with ultra turrax at20000 rpm for 2 minutes. pH was adjusted at 5.40 with formic acid (0.24g). Reaction mixture was stirred at 300 r.p.m. and heated at 45° C. for1 h then at 60° C. for 1 h, and finally at 75° C. for 3 h. The resultingslurry was cooled down (pH=5.50) and neutralized with a solution ofsodium hydroxide (30% in water, 0.2 g, pH=6.67).

TABLE 36 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Oligomeric composition13 40.29 5.99 (10.66% in water) 2. Demineralised water 10.00 To balance3. Perfume oil 21.00 29.28 4. Formic acid 0.24 0.33 5. NaOH (30% w/w inwater) 0.20 0.12 Total 71.73 100Microcapsules 37.

In a 200 ml reactor, a solution of colloidal stabilizer (Alcapsol® 144,7.00 g, pH=5.75) in water (3.00 g) was dissolved in oligomericcomposition 13 as directly obtained in Example 1 (40.29 g). Perfume oil(21.00 g) was added and the reaction mixture was sheared with ultraturrax at 20000 rpm for 2 minutes. pH was adjusted at 5.40 with formicacid (0.25 g). Reaction mixture was stirred at 300 r.p.m. and heated at45° C. for 1 h then at 60° C. for 1 h, and finally at 75° C. for 3 h.The resulting slurry was cooled down (pH=5.50) and neutralized with asolution of sodium hydroxide (30% in water, 0.31 g, pH=6.70).

TABLE 37 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Alcapsol ® 144 (20%w/w in water) 7.00 1.95 2. Demineralised water 3.00 To balance 3.Oligomeric composition 13 40.29 5.98 (10.66% in water) 4. Perfume oil21.00 29.23 5. Formic acid 0.25 0.24 6. NaOH (30% w/w in water) 0.310.25 Total 71.85 100

Microcapsules 36 were prepared with oligomeric composition 13 in theabsence of polyol and colloidal stabilizer whereas microcapsules 34 and37 contain 1% and 2% of colloidal stabilizer, respectively. Stability ofmicrocapsules 34, 36 and 37 was improved compared with comparativemicrocapsules 5 (FIG. 9b /10).

Microcapsules 38:

In a 200 ml reactor, oligomeric composition 13 as directly obtained inExample 1 (40.29 g) was diluted with water (10.00 g). Perfume oil (21.00g) was added. Reaction mixture was sheared with ultra turrax at 20000rpm for 2 minutes. pH was adjusted at 5.42 with formic acid (0.23 g).Reaction mixture was stirred at 300 r.p.m. and heated at 45° C. for 1h30 then at 60° C. for 1 h30, and finally at 75° C. for 2 h. Theresulting slurry was cooled down (pH=5.54) and neutralized with asolution of sodium hydroxide (30% in water, 0.23 g, pH=6.92).

TABLE 38 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Oligomeric composition13 40.29 6.07 (10.66% in water) 2. Demineralised water 10.00 To balance3. Perfume oil 21.00 29.68 4. Formic acid 0.23 0.33 5. NaOH (30% w/w inwater) 0.23 0.10 Total 70.75 100Microcapsules 39.

In a 200 ml reactor, polyol (Ambergum® 1221, 0.69 g) was dissolved inwater (10.00 g) and was added into oligomeric composition 13 as directlyobtained in Example 1 (40.29 g). Perfume oil (21.00 g) was added and thereaction mixture was sheared with ultra turrax at 21000 rpm for 2minutes. pH was adjusted at 5.39 with formic acid (0.17 g). Reactionmixture was stirred at 300 r.p.m. and heated at 45° C. for 1 h then at60° C. for 1 h, and finally at 75° C. for 3 h. The resulting slurry wascooled down (pH=5.39) and neutralized with a solution of sodiumhydroxide (30% in water, 0.18 g, pH=6.68).

TABLE 39 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 0.69 0.95 2. Demineralised water 10.00 To balance 3.Oligomeric composition 13 40.29 5.94 (10.66% in water) 4. Perfume oil21.00 29.03 5. Formic acid 0.17 0.24 6. NaOH (30% w/w in water) 0.180.07 Total 72.33 100Microcapsules 40:

The microcapsules were prepared as described for microcapsule 39, usingoligomeric composition 13 and sucralose to replace Ambergum® 1221 aspolyol.

TABLE 40 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Sucralose 0.70 0.97 2.Demineralised water 10.00 To balance 3. Oligomeric composition 14 40.295.93 (10.66% in water) 4. Perfume oil 21.00 28.99 5. Formic acid 0.200.28 6. NaOH (30% w/w in water) 0.25 0.10 Total 72.44 100

Microcapsules 36 were prepared with oligomeric composition 13 in theabsence of polyol. Microcapsules 39 and 40 contain 1% of two differentpolyols. The presence of polyol in the present invention's process andproduct is not mandatory to improve performance. Stability ofmicrocapsules 36, 39 and 40 was improved compared with comparativemicrocapsules 5 (FIG. 10a /10)

Microcapsules 41:

The microcapsules were prepared as described for microcapsule 36, usingoligomeric composition 14.

TABLE 41 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Oligomeric composition14 50.78 7.01 (8.54% in water) 2. Demineralised water 10.00 To balance3. Perfume oil 21.00 29.08 4. Formic acid 0.21 0.29 5. NaOH (30% w/w inwater) 0.23 0.10 Total 71.73 100

Microcapsules 36 and 41 were prepared with oligomeric composition 13 and14, respectively. Both microcapsules are stable. Stability ofmicrocapsules 36 and 41 was improved compared with comparativemicrocapsules 5 (FIG. 10b /10).

Example 4 Preparation of Comparative Microcapsules, Out of the Scope ofthe Present Invention

Attempt to obtain core-shell microcapsules with the following conditionsprovided the results reported in the Table herein below:

TABLE 1 attempts to form microcapsules with comparative oligomericcompositions Experimental Comparative Attempt condition oligomersResults 1 as described for Comparative No stable dispersion wasmicrocapsule 1 oligomer1 obtained - no microcapsules were obtained 2 asdescribed for Comparative No stable dispersion was microcapsule 3oligomer1 obtained - no microcapsules were obtained 3 as described forComparative No stable dispersion was microcapsule 1 oligomer2 obtained -no microcapsules were obtained 4 as described for Comparative No stabledispersion was microcapsule 2 oligomer2 obtained - no microcapsules wereobtained 5 as described for Comparative No stable dispersion wasmicrocapsule 3 oligomer2 obtained - no microcapsules were obtained 6 asdescribed for Comparative No stable dispersion was microcapsule 1oligomer4 obtained - no microcapsules were obtained 7 as described forComparative No stable dispersion was microcapsule 3 oligomer4 obtained -no microcapsules were obtainedComparative Microcapsules 1: (Microcapsules Obtained Using Prior ArtOligomeric Composition)

The microcapsules were prepared as described for microcapsule 1, usingcomparative oligomers 3 (according to prior art WO 2009/100553).

TABLE 2 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.43 2. Comparative oligomers 3 4.50 4.11 (64% w/win water) 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0028.42 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. NaOH (30% w/w inwater) 0.22 0.20 Total 70.12 100

From FIGS. 1a to 5a it is evident that the present invention'score-shell microcapsules, obtained from the respective oligomericcomposition according to the invention, perform all better than themicrocapsules obtained according to the prior art. The prior artcapsules do not show a thermal stability (no plateau in the TGA)indicating a leakage of the oil throughout the shell, while all theinvention's microcapsules show a significantly improved thermalstability (a plateau in the TGA) indicating no leakage of the oilthroughout the shell (independently from the nature of the polyaminecomponent and/or of the fact that step 2) of the invention's process isperformed or not, e.g. microcapsules 1 and 12, or of the nature of thediamino compound e.g. microcapsules 17).

Comparative Microcapsules 2: (Microcapsules Obtained Using Prior ArtOligomeric Composition and the Present Invention's Process)

The microcapsules were prepared as described for microcapsule 2, usingcomparative oligomers 3 (according to prior art WO 2009/100553).

TABLE 3 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Comparative oligomers 3 4.50 4.04 (64% w/win water) 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0028.12 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 1.00 0.70 7. NaOH (30% w/w in water) 0.31 0.18 Total 71.21 100Comparative Microcapsules 3: (Microcapsules Obtained Using Prior ArtOligomeric Composition and the Present Invention's Process)

The microcapsules were prepared as described for microcapsule 3, usingcomparative oligomers 3 (according to prior art WO 2009/100553).

TABLE 4 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Comparative oligomers 3 4.50 3.99 (64% w/win water) 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0027.72 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 2.00 1.39 7. NaOH (30% w/w in water) 0.28 0.14 Total 72.18 100

From FIG. 6a it is evident that the invention's process is specificallydesigned for the invention's oligomeric composition (microcapsules 9).Indeed, when the invention's process is applied to the prior artteaching, the microcapsules thus obtained (comparative microcapsules 2and 3) performed significantly worse than the prior art microcapsules(comparative microcapsule 1).

Comparative Microcapsules 4: (Microcapsules Obtained Using Prior ArtOligomeric Composition and the Present Invention's Process)

The microcapsules were prepared as described for microcapsule 3, usingcomparative oligomers 5.

TABLE 5 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 15.00 0.42 2. Comparative oligomers 5 4.50 3.99 (47.9% w/win water) 3. Demineralised water 30.00 To balance 4. Perfume oil 20.0027.72 5. Alcapsol ® 144 (20% w/w in water) 0.40 0.11 6. Urea (50% w/w inwater) 2.00 1.39 7. NaOH (30% w/w in water) 0.28 0.14 Total 72.18 100

From FIG. 5b it is evident that working with an oligomeric compositionhaving a molar excess of C₄₋₆ 2,2-dialkoxy-ethanal compared to theglyoxal (comparative microcapsule 4), provides microcapsules which arenot stable; while working with the invention's oligomeric compositionprovides microcapsules which are stable.

Comparative Microcapsules 5: (Microcapsules Obtained Using Prior ArtOligomeric Composition and Invention's Process)

The microcapsules were prepared as described for microcapsule 40, usingcomparative oligomers 3 (according to prior art WO 2009/100553).

TABLE 6 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Colloidal stabilizer0.81 1.49 (Gantrez AN-119BF) 2. Demineralised water 25.00 To balance 3.Polyol (Resorcinol, 30% in water) 2.00 1.10 4. Comparative oligomers 35.51 4.19 (~53.9% in water) 5. Perfume oil 20.00 36.79 6. NaOH (30% inwater) 0.35 0.55 Total 53.67 100Comparative Microcapsules 6: (Microcapsules Obtained Using Prior ArtOligomeric Composition and the Present Invention's Process)

The microcapsules were prepared as described for microcapsule 27, usingcomparative oligomers 3 (according to prior art WO 2009/100553).

TABLE 7 w/w percentage of the various components introduced stepwise inthe dispersion Raw material Amount (g) % (w/w) 1. Ambergum ® 1221 (2%w/w in water) 30.00 0.84 2. Comparative oligomers 3 5.53 5.14 (~53.9% inwater) 3. Guanazole 2.00 2.49 4. Perfume oil 20.00 28.05 5.NaOH (30% inwater) 0.42 0.21 Total 57.95 100

Example 5 Use in Application of the Invention Microcapsules

Body Wash Application

TABLE 1A Body wash formulation Ingredients % w/w 1. Water deionised58.40 2. Carbopol Aqua CC Polymer 8.00 Polyacrylate-1 Crosspolymer(Noveon) 3. Citric Acid (40% aq. sln) 0.50 Citric Acid (Merck) 4.Zetesol AO 328 U Sodium 25.00 C12-C15 Pareth Sulfate (ZSCHIMMER &SCHWARZ) 5.Tego Betain F 50 4.00 Cocamidopropyl Betaine (GOLDSCHMIDT AG(STEINAU)) 6. Glydant Plus Liquid DMDM 0.10 Hydantoin (and) IodopropynylButylcarbamate (LONZA) 7. Sodium Chloride (20% aq. sln) 4.00

Capsules were introduced in body wash formulation, described in Table 1Ato obtain a concentration of perfume at 0.2% w/w. Dispersions werestored at room temperature for 24 hours. The body wash formulation (1ml) was diluted in water (4 ml) and then extracted with isooctanecontaining 1,4-dibromobenzene as internal standard (5 ml). Organicsolutions are then analyzed by GC to measure the leakage of perfume. Theresults on oil-leakage of the microcapsules are reported in Table 1B.

TABLE 1B Leakage in body wash application Oil leakage* Microcapsules (%w/w) Microcapsules 22 18 Microcapsules 24 9 Microcapsules 25 3Microcapsules 29 6 Microcapsules 30 9 Microcapsules 33 10 Microcapsules34 5 Microcapsules 35 9 Microcapsules 36 3 Microcapsules 38 6Microcapsules 39 4 Microcapsules 40 3 Microcapsules 41 4 Comparative 42microcapsule 5 Comparative 58 microcapsule 6 *after 24 hours in the purebase at room temperature

As can be seen from Table 1B, all invention's microcapsules are morestable toward oil-leakage upon storage when compared to prior artmicrocapsules which are CH₂O-free.

Liquid Detergent Application

Capsules were introduced in liquid detergent (composition in Table 2A),with a concentration of perfume at 0.2% w/w. Dispersions were stored atroom temperature for 24 hours An aliquot of liquid detergent (1 ml) wasdiluted in water (4 ml) and then extracted with isooctane (5 ml)containing 1,4-dibromobenzene as internal standard (150 mg/l). Organicsolutions were then analyzed by GC to measure the leakage of perfume.The results on oil-leakage of the microcapsules are reported in Table2B.

TABLE 2A Liquid detergent formulation Ingredients % w/w  1. Borax 1-2 2. Citric Acid 2-3  3. Diethylenetriamine Pentaacetate 0.1-0.5 (SodiumSalt)  4. Amylase 0.1-0.2  5. Protease 0.1-0.2  6. DisodiumDiaminostilbene 0.0001-0.001  Disulfonate  7. Diquaternium EthoxySulfate 0.1-0.2  8. Polyethyleneimine Ethoxylate 0.1-1   9. CalciumFormate 0.01-5   10. Dimethicone 0.001-0.005 11. Ethanolamine 0.5-5  12.Propylene Glycol 0.05-0.1  13. Sodium Formate 0.01-5   14. AlcoholethoxySulfate 7-8 15. Lauramine Oxide 1-6 16. Laureth-9 1-5 17. LinearAlkylbenzene Sulfonate 1-2 18. Water up to 95

TABLE 2B Leakage in liquid detergent application Oil leakage*Microcapsules (% w/w) Microcapsules 24 9 Microcapsules 25 8Microcapsules 29 9 Microcapsules 30 8 Microcapsules 33 17 Microcapsules34 11 Microcapsules 35 9 Microcapsules 36 6 Microcapsules 37 27Microcapsules 38 22 Microcapsules 39 7 Microcapsules 40 6 Microcapsules41 5 Comparative 94 microcapsule 5 Comparative 66 microcapsule 6 *after24 hours in the pure base at room temperature

As can be seen from Table 2B all invention microcapsules are more stabletoward oil-leakage upon storage when compared to prior art microcapsuleswhich are CH₂O-free.

Softener Application

Microcapsules were diluted in a fabric softener (composition: Stepantex®VK90 (Stepan) 16.5%, calcium chloride 0.2%, water 83.3%) to obtain aconcentration of perfume at 0.8% w/w. Dispersions were stored at roomtemperature for 24 hours. An aliquot of softener (1 ml) was diluted inwater (4 ml) and then extracted with isooctane (5 ml) containing1,4-dibromobenzene as internal standard (150 mg/L). Organic solutionswere then analyzed by GC to measure the leakage of perfume. The resultson oil-leakage of the microcapsules are reported in Table 3B.

TABLE 3B Leakage in fabric softener application Oil leakage*Microcapsules (% w/w) Microcapsules 25 17 Microcapsules 33 13Microcapsules 34 9 Microcapsules 35 7 Microcapsules 36 4 Microcapsules38 5 Microcapsules 39 4 Microcapsules 40 2 Microcapsules 41 5Comparative 92 microcapsule 5 Comparative 73 microcapsule 6 *after 24hours in the pure base at room temperature

As can be seen from Table 3B all invention microcapsules are more stabletoward oil-leakage upon storage when compared to prior art microcapsuleswhich are CH₂O-free.

What is claimed is:
 1. An oligomeric composition for the preparation ofcore-shell microcapsules, the composition obtained by reactingtogether: 1) a polyamine component in the form of melamine or of amixture of melamine and at least one C₁₋₄ compound comprising two NH₂functional groups; 2) an aldehyde component in the form of a mixture ofglyoxal, a C₄₋₆ 2,2-dialkoxy-ethanal and optionally a glyoxalate, saidmixture having a molar ratio glyoxal/C₄₋₆ 2,2-dialkoxy-ethanal comprisedbetween about 1/1 and 10/1; and 3) a protic acid catalyst; wherein thecomposition provides a stable emulsion that facilitates formation ofcore-shell microcapsules.
 2. An oligomeric composition according toclaim 1, wherein the polyamine component is a mixture of melamine and atleast one C₁₋₄ compound comprising two NH₂ functional groups and saidC₁₋₄ compound comprising two NH₂ functional groups is selected amongsturea, 1H-1,2,4-triazole-3,5-diamine and mixtures thereof.
 3. Anoligomeric composition according to claim 1, wherein said mixture has aratio melamine/C₁₋₄ compound comprising two NH₂ functional groupscomprised between about 2/1 and 1/3.
 4. An oligomeric compositionaccording to claim 1, wherein said aldehyde component has a molar ratioglyoxal/2,2-dialkoxy-ethanal comprised between about 2.2/1 and 6.5/1. 5.An oligomeric composition according to claim 1, wherein said C₄₋₆dialkoxyethanal is 2,2-dimethoxy-ethanal, 2,2-diethoxy-ethanal ormixtures thereof.
 6. An oligomeric composition according to claim 1,wherein said aldehyde component comprises a glyoxalate.
 7. An oligomericcomposition according to claim 1, wherein said glyoxalate has a molarratio glyoxal/glyoxalate of between about 4/1 and 1/1.
 8. An oligomericcomposition according to claim 1, wherein the polyamine component andthe aldehyde component are admixed in a ratio such that the molar ratio(total amine functional group)/(total free aldehyde functional group) iscomprised between about 2/1 and 1/2.
 9. An oligomeric compositionaccording to claim 1, wherein said protic acid catalyst is selectedamongst mineral acids, C₁₋₆ mono or dicarboxylic acids and mixturesthereof.
 10. A process for the preparation of a core-shell microcapsulefrom an oligomeric composition, which comprises: preparing anoil-in-water dispersion that includes the oligomeric composition ofclaim 1; heating the dispersion; cooling the dispersion to obtain thecore-shell microcapsule; and optionally, drying the final dispersion toobtain a dried core-shell microcapsule.
 11. The process according toclaim 10, wherein the oil is a perfume oil, and the dispersion comprisesbetween about 10% and 50% of oil, the percentage being expressed on aw/w basis relative to the total weight of the dispersion.
 12. Theprocess according to claim 10, wherein the dispersion comprises betweenabout 1% and 10% of oligomeric composition, the percentage beingexpressed on a w/w basis relative to the total weight of the dispersion.13. The process according to claim 10, wherein the dispersion furthercomprises up to 0.5% of at least a stabilizer, and up to 2% of at leasta polyol, the percentage being expressed on a w/w basis relative to thetotal weight of the dispersion.
 14. The process according to claim 10,wherein the C₁₋₄ compound comprising two NH₂ functional groups ispresent in the dispersion in an amount of about 5% and 100%, thepercentage being expressed on a w/w basis relative to the total weightof the resin.
 15. A core-shell microcapsule made from the composition ofclaim
 1. 16. A perfuming consumer product which comprises, as aperfuming ingredient, at least one core-shell microcapsule, as definedin claim 15 which includes a perfume oil therein; wherein the consumerproduct is a fabric care product, a body-care product, an air careproduct or a home care product.